And I would tend to agree…

Paper is the source of light and the foundation for your paint.

But paper’s quality and handling properties vary enormously depending on the type and brand.

This makes choosing paper somewhat confusing. Especially for beginners!

So… in this comprehensive guide, I will tell you all you need to know about watercolor paper and how to make an informed choice about what to use.

What is watercolor paper?

Watercolor paper is a relatively thick and absorbent paper specially designed for wet mediums like watercolors. It enhances the luminosity of watercolor pigments to their fullest. It can be made from cotton fibers, wood pulp, or both. It’s available in different textures and various thicknesses, although the most commonly used type is cold press 300 gsm / 140 lb.

That’s a fairly broad answer. 

As you can probably guess, there are many variations within the characteristics described above… The composition, thickness, and surface finish ALL affect how the paper handles with watercolors.

Also, the materials used to make watercolor paper will determine its strength, longevity, and price.

We’ll get into all these details below… 

Faced with the abundance of different types of paper on the market, some beginners ask if they really need a special kind of paper to paint with watercolor.

Just so you have no doubts, let me explain…

Do you really need watercolor paper? 

Yes, you need to use a special kind of paper to paint correctly with watercolors. Because this painting medium is so wet compared to others, you need a surface that can withstand a lot of moisture! 

The clue is in the name – they don’t call it “watercolor paper” for nothing

What is the difference between watercolor paper and normal paper? 

Watercolor paper is thicker and generally more robust than ordinary paper stock. It also has a special finish known as “paper sizing” that alters the absorbency of the paper. This treatment allows the paint to be absorbed into the paper fibers in a balanced way, allowing the artist time to play with the paint before it dries.

Note: sizing isn’t always only a surface coating. A lot of papers are also internally sized. 

So what is the best watercolor paper? 

For watercolor painting, the best quality paper is made of 100% cotton, is acid-free, with a neutral pH value. It will also be “archival,” meaning the paper will preserve its properties over a long period of time, and your painting won’t fade.

Cotton paper:

Cotton is stronger and more durable than wood cellulose (the stuff ordinary printer paper is made from). Cotton is a pure source of cellulose. Its fibers are longer, making it tougher and more resistant.

The strength of cotton makes it suitable for use with wet mediums like watercolor. This type of paper is more durable and “dimensionally stable,” meaning it retains its shape better. If you’ve ever painted on watercolor paper, you’ll know it “buckles” and deforms when heavily wetted. Although cotton paper still warps when soaked, it will perform slightly better than wood-based paper.

Cotton also has excellent absorbency properties.

And cotton is also naturally white, which means the paper needs little bleaching or other treatments to alter the color appearance (see “tint & color” below for more about this).

Acid-free / pH neutral:

If you remember from your chemistry classes, pH is a measure of the acidity of a substance

Acid-free and pH-neutral paper indicates it was made using an alkaline pulp and has a neutral pH (pH 7). Wood pulp is naturally acidic. This acidity is removed to avoid yellowing and prevent the sheets from deteriorating over time.

But cotton is naturally archival and pH neutral.

Archival properties:

Acid messes up the longevity of paper. It causes the paper to discolor over time and can even degrade certain paint pigments. 

That’s why you should look for acid-free paper.

But cotton is naturally archival and pH neutral!

This property renders the paper archival, meaning it remains stable over time without deteriorating.

After all… You want your masterpieces to last for centuries! Right?

Tint and Color Appearance:

Another aspect of watercolor paper worth mentioning is the tint or general color appearance. 

Most papers are not pure white. They need some kind of treatment to make them brighter or more uniform in appearance. 

As mentioned above, cotton paper is “naturally” white but not bright white. Some manufacturers add OBAs (optical brightening agents) to make paper pure white. 

Extra-white papers are altered with these chemicals. 

But OBAs do not last forever! 

They fade over time and cause watercolor paints to shift in color. That’s why artist-quality archival papers are not whitened in this way. For longevity, you should favor “natural” off-white paper.

Characteristics of the best kind of watercolor papers:

To sum up, these are the essential properties of artist watercolor sheets. To choose the best paper, remember to look for these features:

• 100% Cotton
• Acid-free
• pH neutral
• Archival
• Traditional color

That being said, cotton paper is also the more pricey option. If you’re starting out with watercolors, it’s understandable that you’re reluctant to splash out on high-priced paper… 

What is the best watercolor paper for beginners? 

The ideal type of watercolor paper for absolute beginners is commonly known as academy-grade paper. These are generally made out of cheaper wood cellulose. This paper has a different quality, durability, and archival properties than artist-grade paper. But it’s more affordable for getting started with watercolors.

(In addition, the most appropriate texture and weight for beginners is cold press paper weighing 300gsm / 140lb. You can read more about textures and weights below.)

It’s true… The “best” watercolor paper can be pretty expensive. The highest quality is generally classed as “artist” grade paper. As a result, this may not be the perfect option for beginners. Spending large amounts of money and living in fear of ruining the paper isn’t fun!

As an alternative, manufacturers make student-grade papers that are more affordable. This makes them better suited to artists who are getting started with this medium and want to experiment.

They are cheaper because they use lower-grade materials such as wood pulp. The internal and surface sizing is also usually poor quality!

Surface handling properties (Sizing)

Before you read further, it’s helpful to talk about sizing. This is an essential factor affecting the paint’s handling properties on the paper surface. Traditionally, the substance used for sizing is gelatin.

All watercolor paper is sized to alter its absorbency. But sizing involves finding a delicate balance. The paper needs to be sufficiently absorbent to fix the pigments to the surface – but at the same time, not so porous that it sucks the paint deep into the paper fibers, making the colors look dull…

I suggest you read my in-depth article “watercolor paper sizing” for a better understanding.

Types of watercolor paper 

The different types of watercolor paper are categorized by three main properties: academy or artist quality, surface texture, and thickness (defined by the weight).

Within these parameters, there’s a lot of choice. 

Academy-type papers are great for becoming familiar with watercolor painting. But they are limited. They won’t handle as well as artist-grade paper. 

However, there are very good reasons for using both grades. Let’s discuss the differences between these two types of paper:

Academy vs. artist-quality watercolor paper

I consider academy paper essential for beginning with watercolors. It allows you the freedom to splash paint around and develop your early skills without worrying about price constraints.

But as you progress, you’ll benefit by transitioning to artist-grade paper to experience watercolors to their fullest.

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Academy watercolor paper 

This is the economic version of watercolor paper. It will help you become familiar with the paint before moving on to more expensive sheets.

But getting good results is actually more difficult!

You are more likely to get streaky brush marks or blotches.

The paint reacts differently on these surfaces and is actually more challenging to control.

Which is a bit of a paradox! Because these papers are sold as “academic” grades, but they are, in fact, more difficult to use than pro “artist” grade papers!

Crazy huh?

That is not to say you can’t paint great artwork with this paper. You will just have to accept blemishes and some quirky handling properties. As your skills evolve, you’ll adapt to this type of paper very well and learn to adjust your painting technique. 

This type of paper is made from wood pulp and is less durable. It is likely to have been treated to modify the paper’s acidity and may contain brightening agents to make it whiter. 

Some of my favorite academy-grade papers include the following:

• Canson XL series 
• Arteza Watercolor Paper (Amazon link)

Artist watercolor paper 

You’ll really feel a difference when you shift to artist-grade paper. 

This paper type is made from 100% cotton, and the sizing is well-adjusted. This means watercolor paints become easier to control. Notably, the dispersion of paint pigments when working wet-on-wet is smooth and uniform. You can create soft blends and transitions in color. Artist-grade paper gives you time to work before it dries. And this type of paper also handles perfectly for glazing (layering paints).

My favorite artist papers include:

• Arches Cold Press
• Fabriano Artistico Traditional White

Watercolor Paper Textures (Hot press vs. Cold press vs. Rough)

There are three categories of watercolor paper texture, ranging from smooth to coarse: these are hot press, cold press, and rough. Hot press is smooth, cold press has a medium texture, and rough paper has the most pronounced grain.

Each of these textured surfaces has a different interaction with the paint. You will notice that watercolor paint performs in a distinct way on each surface finish. 

Here’s an overview of each one:

Hot press

The hot-press paper has the smoothest surface finish. The name comes from the production process of pressing the paper between hot metal rollers to generate a smoother texture. 

This surface is perfect for detailed work. There’s no grain to interrupt the flow of your brush strokes. It’s also well adapted to mixed media techniques like pen and wash.

However, the surface is harder and less absorbent than cold press or rough paper. This means it can be tricky to work with as a beginner because the paint absorbs slowly, and watercolor washes can pool on the surface, increasing the risk of unpredictable effects such as back runs or blooms.

Cold press

Cold-pressed paper is also classified as NOT, which stands for “not hot-pressed.” Which I guess is a bit of a mouthful! So it’s more commonly referred to as “cold press.” This name describes the manufacturing process where the paper is pressed between cold metal rollers. The rollers are covered in felt, which imparts a slight texture.

Cold press is more absorbent than hot press paper (but generally less absorbent than rough).

These qualities make it the most “forgiving” type of paper for newcomers. It has a reputation for being easy to use and can tolerate some corrections. 

Cold press textures accept some detailed brushwork, but artists can easily make textured brush strokes. This makes the paper well-suited to a wide range of painting styles.

Rough

You guessed it! Rough paper is the most heavily textured painting surface for watercolors.

Rough papers are pressed between coarse felt sheets, which emboss the texture onto the damp paper as it dries. 

Rough papers tend to be the most absorbent. Brush strokes and irregular watercolor effects such as granulation are more pronounced. 

This makes it less easy to work with if you’re new to watercolors but well adapted to expressive painting styles.

Which is better: cold press or hot press watercolor paper?

Cold press and hot pressed papers are each appropriate to different painting styles and skill levels. As a beginner, the more absorbent and moderately textured surface of cold-press watercolor paper provides an easier surface than smooth hot-press sheets.

I often get asked which type is better, but that’s not the real question…

If you enjoy irregular watery effects or want to paint a lot of detail, try hot-press paper. If you prefer an easy-going surface and expressive dry brush techniques, cold-press is better.

For a more detailed comparison of these two options, I recommend reading my article on cold-press vs hot-press paper.

What paper texture is best for watercolor? 

Cold press moderately textured paper is the first choice of most watercolorists. It is the most flexible surface finish because it adapts to so many different ways of painting.

Paper Weight & Thickness

Different thicknesses of watercolor paper are expressed by weight. The heavier the paper, the thicker it is. The most popular and versatile paper weight is 140 lb / 300 gsm.

All manufacturers express weight in two measures: 

• lb (pounds per ream) 
• gsm (grams per square meter).

The reason paper thickness is important is because of the paper’s tendency to warp when wet.

The thicker the paper, the less it warps (but it also gets more expensive!)

The best compromise in terms of thickness is 140 lb (which is approximately the same as 300 gsm). This warps less than 90 lb (185 gsm) paper but will still buckle more than very thick 300 lb (640 gsm) paper.

You can begin to see why this is the most popular type of watercolor paper!

I suggest you read this article for a more detailed explanation of paper weights.

Paper Sizes and Formats

Watercolor paper is available in a confusing array of formats and dimensions. However, the most common and versatile form is 9 by 12 inch watercolor pads.

Pads, blocks, and sheets

Watercolor sheets are usually sold in traditional large-sized formats, the biggest being the imperial full sheet (22 by 30 inches). Not all artists, particularly beginners, need paper this large.

Watercolor pads, on the other hand, are extremely handy. The sheets of paper are glued along one edge, making them easy to remove. They’re sometimes also available as spiral-bound pads. Pads offer a wide variety of smaller, ready-to-use dimensions (compared to sheets, for example).

Blocks are also available in a wide range of dimensions. Blocks are glued on all 4 sides. This holds them slightly flatter when working with wet watercolor washes (but doesn’t completely prevent buckling). 

However, blocks prevent you from tracing! You have to freehand your pencil outlines onto the paper, which is time-consuming and potentially harms the paper as you erase sketch lines. 

That’s why my favorite format is pads.

Further reading: see my article on watercolor paper sizes for a more in-depth comparison.

Personal Paper Preference

Taking into account all the various paper parameters, for me, the best watercolor paper is as follows:

• Artist grade 100% cotton cold press 140 lb 300 gsm arches 9×12 inch paper pads.
• Academy grade cold press 140 lb 300 gsm 9×12 inch Canson Xl pads.

I consider these the best all-round surface texture, thickness, size, and format for everyday watercolor painting. I also keep larger dimensions of the same paper to hand for painting bigger subjects – usually about 10 x 14 inches.

FAQ

Which side of watercolor paper do you use?

The manufacturing process creates a slightly different surface finish to watercolor paper. To find out whether this makes a difference to the handling qualities of watercolor paints, I examined this question in this article.

How do you stretch watercolor paper?

You’ll notice that watercolor paper bends and distorts when wet. The only way to have a completely flat surface while working is to stretch the paper. Read my guide to stretching watercolor paper here…

Do you have to wet watercolor paper before painting?

When to wet paper or not can be a confusing question for beginners. I will tell you everything you need to know in this article.

The post Best Paper for Watercolor (Expert’s Ultimate Guide!) first appeared on Watercolor Affair.

It can be pretty confusing!

It’s easy to get lost in all the different formats and sizes of paper for painting with watercolors. It’s enough to make your head spin!

So below, I’ll go over what options are available and answer some of the most common questions about the sizes of watercolor paper you can find on the market…

What are the different sizes of watercolor paper?

The US and Europe have different paper size standards. They also use different measurements – imperial (inches) and metric (cm). So depending on your location, the most common paper sizes you’ll come across are as follows:

• 7 x 10 inches
• 9 x 12 inches (known as ARCH A size)
• 10 x 14 inches
• 12 x 16 inches
• 14.8 x 21 cm (A5)
• 21 x 29.7 cm (A4)
• 29.7 x 42 cm (A3)

But in reality, the sizes available are also related to the chosen format. In other words, rolls, sheets, pads, blocks… and even postcards are only available in specific dimensions.

Let me give you an example…

The 9 x 12-inch format is available in both watercolor blocks and pads. But the similar-sized A4 format is only available as pads! Go figure!

Watercolor sheet size

Another good example is watercolor paper sheets. The handmade paper-making process uses a traditional wooden frame mold. Other sheets are derived from a cylinder mold machine. The resulting sheet sizes depend on the size of the molds, which use imperial measurements, and each has its own sheet name. The best-known examples are:

• Full sheet watercolor paper size (Imperial): 22 x 30 inches 
• Half sheet watercolor paper size (Half Imperial): 15 x 22 inches 
• Quarter sheet watercolor paper size (Quarter imperial): 11 x 15 inches 

Standard Watercolor Paper Sizes

Standardization of paper dimensions became important for commercial reasons. For example, the British Imperial system of paper dimensions was created in 1836. (Conventional measurements and units facilitated trade and commerce so that goods could be accurately measured and valued).

Even today, artists often refer to paper sheets by the standard imperial names.

But as you can see from the abovementioned sizes, not all watercolor paper sizes conform to one specific standardization! Paper sizes can vary from country to country. Sometimes traditional formats remain in use. Other times manufacturers seem to invent their own rules! (Just take a peek at Fabriano’s watercolor paper, and you’ll see what I mean).

An international standard was adopted around 1975, known as the ISO standard (International Standards Organization). This is the well-known “A” format that uses metric dimensions. Many manufacturers worldwide produce paper according to these sizes. 

A4 is the most commonplace paper size in Europe! Everyone and their granny knows this is what you put in the printer!

But North Americans tend to use a different system of paper sizes and names than the rest of the world.

Hmmm…

In the US, the equivalent of an A4 sheet is the Letter size: 8,5 x 11 inches. But you won’t find watercolor paper in this format either! The closest match is the popular 9×12-inch format.

Is your brain getting numb yet?

So why so many obscure and unusual sizes for watercolor paper?

One reason could be “proportion.”

In fine arts like watercolor painting, aesthetics are important. So the proportions of the sheet (its height and width) add to the overall feeling of balance and harmony of a finished painting. 

So this variation in paper size caters to the diverse needs and preferences of artists who work with watercolors. Artists can then choose from non-standard sizes to suit specific needs.

Sheet sizes originated from the traditional framing sizes of hand-held molds. These were made using dimensions that looked good for the finished piece of artwork. As a result, they were more aesthetically pleasing!

The standard “A” sizes like A4 and A3 are sometimes criticized by artists as less artistically pleasing. This is probably why we get a range of non-standard sheet dimensions like these:

• 7 x 10 inches (aspect ratio 10:7 – more elongated)
• 9 x 12 inches (aspect ratio 4:3)
• 10 x 14 inches (aspect ratio 7:5 – more elongated)
• 12 x 16 inches (aspect ratio 4:3)

None of these lengths match any standard paper format, except perhaps the 9×12 inch sheet. This dimension corresponds to the “ARCH A” paper size.

If you compare the proportions of these imperial sized sheets to the A4, A3 formats, you’ll see that the “A” formats are slightly longer and thinner. I admit, I prefer the 9×12 in option

Large Watercolor Paper

Some artists prefer to buy large sheets and cut them down for economic reasons. Others just like to paint on colossal paper formats! 

So what is the largest size of watercolor paper? 

Rolls of watercolor paper are the format that offers the biggest dimensions. Arches make rolls up to 51 inches wide and 10 yards long. Other typical roll sizes are 36 inches wide and 10 yds in length.

Another option for large paper is to buy it in packs of sheets. But if your objective is to save money, you must be careful and calculate correctly.

For example, you can buy 5 imperial-sized sheets of Arches watercolor paper for about $100. If you cut this down into quarter imperial sheets, you would end up with 20 pages ($5 per sheet – Amazon). 

However, you can get a 10 x 14-inch watercolor block for under $50! That’s more than half the price… ($2.5 per sheet – Amazon)

There’s a significant advantage to choosing the most popular paper sizes available. Because of its popularity, this should help keep market prices low. I like the 9×12-inch format, which probably works out to be the cheapest. For example, at the time of writing, you can get a 9×12 inch pad of Arches cold press paper for 19 bucks! ($1,58 per sheet!)

Have fun!

Related reading: for a complete overview read my article about the “best paper for watercolors“

The post Watercolor Paper Sizes (Everything You Need To Know!) first appeared on Watercolor Affair.

And no… I’m not talking about the dimensions of the sheet

As you begin to understand more about your art materials, at some point, you’ll come across the topic of sizing. 

Sizing is a substance that is added to paper to modify its handling properties. Each type and brand of watercolor paper is sized differently. It’s a traditional method of making watercolor paper perform as it should. Without it, your paint would do all kinds of weird things on the sheet’s surface. 

As a beginner, I used to find this pretty confusing! 

What exactly does sizing do, and how does it affect the way you paint with watercolors?

In this article, I’ll explain everything you need to know.

What is watercolor paper sizing?

Sizing is used to alter the absorbent qualities of paper. Watercolor paper absorbs paint directly into the fibers like a sponge without sizing. Traditional sizing uses gelatin, but plant-based and synthetic sizing are also commonly used. Size can be applied internally, externally, or sometimes both. 

Sizing influences three properties of watercolor paper:

• Its Absorbency
• Its Strength
• The Color appearance

Artist-quality paper is traditionally sized with gelatin (an animal-based by-product of the food industry). This is a naturally transparent and water-soluble substance, but it has a slightly yellowish color. Adding gelatin produces a creamy-colored paper rather than bright white. 

The strength of the paper is also influenced by sizing. Surface sizing provides a hard coating that protects the paper from wear and abrasion.

Finally, the degree of internal and surface sizing modifies the permeability and absorbent qualities of the sheet. 

External vs. internal sizing of watercolor paper 

A quick note about two different methods of sizing commonly used in the production process:

• Internal sizing
• External sizing

Internal sizing happens in the early stages of the paper manufacturing process. It is added to the wet paper pulp before the sheets are formed.

External sizing (also called tub or surface sizing) happens at the end of the process. First, the paper sheets are dried and then dipped in a gelatin bath, coating the external surface.

External size bestows a crisp hard outer surface on the paper. In contrast, internal sizing modifies the structural properties slightly and helps to keep sheets stiff and more dimensionally stable. 

Why is sizing important?

Most artist-quality watercolor paper is mold-made or handmade and purposely designed for painting with wet media. Sizing is a vital ingredient because it significantly affects the handling properties of the paper during painting. 

Good watercolor paper brings out the best in watercolor paint and highlights its best qualities! 

That’s the whole point

The sizing agent allows the wet paint to remain on the surface long enough for you to work without sucking colored pigments deep into the fibers. 

If the pigments are entirely absorbed, you can’t continue to play with the paint. It fixes in place. Most good watercolor papers allow time to move pigments around in a wet wash or lift color off the surface if needed. On the other hand, if sizing is too strong (hard), the pigments never get absorbed and float around on the surface for too long.

At the same time, thanks to the sizing, the slightly impermeable surface allows the dry paint strokes to settle near the surface of the paper. This emphasizes the colors making them more luminous and vibrant! (if the sizing is poorly done, paint gets soaked up, resulting in flat-looking colors).

As you can probably tell… Good sizing is a bit of a balancing act! It has to resist the wet paint just enough to improve its handling properties, but not too much, or it would never stay put!

The amount of sizing

The amount of sizing used during the paper-making process significantly impacts how the paper handles during painting. 

There are three general categories of sized paper:

• Unsized paper
• Soft sized
• Hard sized

Unsized paper (sometimes called water-leaf) is the kind that absorbs moisture the most. Think of blotting paper or the filter paper used to make coffee. Paper towels and kitchen rolls are other good examples.

Soft-sized paper includes things like newsprint. (These are perfect for printing because the ink needs to absorb deep into the fibers and stay there.)

Hard-sized includes all types of coated art paper, such as watercolor paper

Of course, these are broad categories, and the degree of sizing used in the production process differs quite a bit. 

Handmade papers will have the biggest discrepancies from one batch to another. 

And each brand has its own way of doing things! 

As a result, Arches watercolor paper will behave slightly differently from Strathmore or Fabriano Artistico. The amount of sizing can be softer or harder depending on the manufacturer’s choice.

This is where things get tricky!

Your brand choice can make a big difference in how you paint.

Sized papers improve the workability and handling properties of the paper surface. Well-sized watercolor paper offers a perfect balance of absorption and, at the same time, allows the paint to flow and disperse correctly on the paper surface.

This is important because it influences the watercolor techniques you employ while painting.

For example, glazing is an essential technique in watercolor painting (this is where you apply subsequent layers of color, one on top of the other). However, for glazing to work properly, you must let the underlying paint dry before applying the next layer. 

Now imagine a sheet of watercolor paper that isn’t correctly sized. If the sizing prevents the pigments from fixing to the paper fibers, glazing becomes problematic. Each new brushstroke will reactivate the first layers. All the colors mix and blend together each time you paint a new glaze. 

Lifting is also a helpful technique for watercolor artists and is affected by sizing (this is a method where you remove paint from the surface by re-wetting it or soaking up some of the colors from the paper with a brush). 

If the sizing is too soft (too absorbent), the pigments are drawn deep into the paper fibers. Therefore, they will be difficult to remove using lifting techniques.

Wet-on-wet techniques are also widely used in watercolor painting. 

Some types of paper (student-grade paper in particular) have very hard sizing, preventing the pigments from being absorbed and causing excessive dispersion on the surface. 

Personally, I’ve become accustomed to using Arches. The surface makes it relatively easy to handle glazing techniques. You have time to play with the paint, and wet-on-wet methods disperse perfectly. 

Keep in mind the handling qualities of different grades and brands of paper can vary widely. Student-grade watercolor sheets, in particular, have poor sizing. Try to find the one that suits your technique the best. 

FAQ

That said, people often ask a few other questions about sized papers. Here are some replies to a few common queries:

Do I need to size watercolor paper? 

All watercolor paper is pre-treated with sizing, so you do not need to size your paper. So long as it is labeled “watercolor,” it should be suitable for wet media. 

Some artists use sizing mixed with paint to create a “ground .”They apply this as a light wash over the paper before starting a painting as a way to add an aesthetic effect.

But I’ve never found this necessary!

Does watercolor paper have sizing on both sides? 

The majority of watercolor paper is sized on both sides. This is a result of the traditional paper-making process. The sizing is either added to the wet pulp or applied to the surface by dipping it in a gelatin bath. So inevitably, both sides of the paper are sized. 

Does soaking watercolor paper remove the sizing?

Sometimes artists stretch their watercolor paper to ensure a flat surface while painting. Unfortunately, the paper is drenched during this process, which disturbs the surface sizing. 

If you have ever stretched watercolor paper, you may have noticed that the surface texture ends up slightly fuzzy after stretching. This is because the expansion and contraction of the paper fibers and the loosening of the surface sizing cause this effect.

The surface sizing is still there, but there will be less of it. Less gelatin on the sheet also means you can do less lifting or scraping to remove errors.

Can the sizing on watercolor paper go bad?

Over time paper sizing can deteriorate, or the paper might have bad sizing for some reason. This can produce patchy-looking results when you apply a wash of color. 

You can also get splotchy marks where too much sizing has been applied or grease marks from too much handling. 

Sometimes this can be recovered by soaking and brushing the surface with clear water. It will dissolve the surface sizing, redistribute it across the surface, and help wash away any oily marks.

Further reading:

For an in-depth look at paper sizes read this !

A complete over view of watercolor paper

The post Watercolor Paper Sizing (Explained!) first appeared on Watercolor Affair.

But this can be a very confusing topic, even for artists who have been painting for a while.

In this article I’ll help you understand how the weight of watercolor paper affects your painting experience and how to make the right choices.

Let’s get to it !

Watercolor Paper Weight

A lot of “artist quality” paper is made using a traditional cylinder mould process. This is a slow method of production which ensures a uniform surface and robust quality.

And it’s actually the best way to make heavier weights of watercolor paper, which comes in very handy for water-based art applications.

Paper weight is an issue for watercolor artists because of the problem of “buckling” (the way the paper warps when wet).

Light weight paper will buckle a lot, whereas heavier weights of paper warp less.

So for more watery applications very light weight paper will need stretching. *

But stretching can be a time consuming process. So maybe you need a heavier grade of paper?

On the other hand, heavier weights of paper are more expensive…

So how do you know which weight of paper to choose?

What does Watercolor Paper Weight Mean?

The weight of watercolor paper is a way of describing its thickness.

So when you compare weights, you’re really talking about how thick the paper is.

The higher the weight, the thicker the paper.

As you can imagine, different thicknesses behave differently when subjected to a lot of water, as is the case with watercolor painting. So finding the appropriate weight for the amount of water we typically use in watercolor painting is a key characteristic to take into account.

But the weight of paper can be expressed in two different ways:

Pounds (lbs)

Grams per square meter (gsm or g/m²)

Unfortunately, this is where things get tricky. Because these two measurements are calculated in different ways, which can get pretty confusing.

Watercolor Paper lb (pounds per ream)

Traditionally, weights are expressed using the British Imperial system, in pounds per ream.

A ream is made up of 500 sheets. And the size of each standard sheet in a ream is called the “basis size”.

In watercolor painting the basis size of paper is the imperial full sheet which measures 22” by 30” inches.

​

So the weight that you see printed on the label of watercolor paper is actually the weight of:

• 1 ream of imperial full sheets.

or

• 500 sheets measuring 22” x 30” inches.

The problem with the imperial unit of measurement is that not all papers use the same “basis size” for measuring a ream.

For example, the standard size of a sheet of drawing paper measures 24” x 36” inches which is quite a bit bigger than the basis size of watercolor paper. As a result, a sheet of 90 lb drawing paper does NOT weigh the same as a 90 lb sheet of watercolor paper !

Watercolor Paper gsm (grams per square meter)

To overcome this problem we now use a metric system which measures the weight in grams per square meter or gsm:

This is the weight in grams of a single sheet of paper which is exactly 1 square meter.

GSM is a much more straightforward way of measuring and comparing paper weight because it doesn’t take into account the standard sizes of different types of paper.

The “grams per square meter” system always compares the same size sheet (1m x 1m).

So instead of comparing apples with oranges, now you’re comparing apples with apples!

Often you’ll find both measurements are expressed. For example 300 gsm paper is roughly the equivalent of 140 lb.

After a while you will probably settle on a favorite brand of watercolor paper and a particular weight (my own preference for finished paintings is Arches cold press 140 lb / 300gsm). 

Sometimes you might come across a pad of paper where the weight is only expressed in pounds, or maybe the metric gsm method. In cases like this it’s very useful to understand the different equivalents in weight between both systems…

Watercolor Paper Weight Conversions

For convenience, here are some of the most common watercolor paper weight conversions for these two systems of measurement:

​

(Remember that these are equivalents and can vary slightly from one manufacturer to another).

All this is very well, but what weight should you choose to get the best out of your watercolor painting ?

Let’s try to simplify things…

After shopping around for watercolor paper for a while you will probably notice the most commonly produced weights are 90 lb (185 gsm), 140 lb (300 gsm) , and 300 lb (640 gsm).

It’s easiest to think of these weights as “thin, medium, and thick”:

• ​90 lb (185 gsm) = thin
• ​140 lb (300 gsm) = medium
• ​300 lb (640 gsm) = thick

​

What is a Good Weight for Watercolor Paper

For me (and a lot of other watercolor artists) the best watercolor paper weight is:

140 lb / 300 gsm.

This weight is not too thin and not too thick. It’s just the right weight to avoid warping for most types of wet painting applications. And it’s cheaper than heavier types of paper!

Just don’t get the 300 gsm mixed up with the 300 lb paper !

But how does 140 lb paper really compare with thicker or thinner options ? For comparison, below are the answers to a few common questions:

Difference between 90 lb and 140 lb Watercolor Paper?

90 lb / 185 gsm paper might be fine for some sketching situations but personally I avoid using this weight for painting. It’s just too thin and buckles easily, which makes controlling the movement of paint on the surface very tricky.

Some artist grade paper manufacturers don’t even bother making 90lb paper !

140 lb / 300 gsm on the other hand is a good thickness for most uses.

Is 90 lb Paper Good for Watercolor?

Not really! 90 lb paper is more like the kind of weight you would want for decent drawing paper. If you’re going to apply watercolors on top of sketches, go for something heavier.

What is the difference between 140 lb and 300 lb watercolor paper?

140 lb (300 gsm) paper is a medium thickness paper that accepts water soluble media very well, but if your style of painting involves a lot of wet-on-wet techniques, or you paint large washes, you might need to stretch this type of paper beforehand.

Alternatively you could go for 300 lb / 640 gsm paper !

This is almost as thick as card and won’t buckle in most watercolor painting situations.

But it is a bit pricey !

If you can I would suggest trying both these weights. It’s possible you’ll fall in love with one or the other Get yourself a small pad of each option for testing – for example:

Arches cold press 140 lb / 300 gsm

Arches cold press 300 lb / 640 gsm

For a quick explanation of watercolor weights, watch my 1 minute YouTube version above…

The post Watercolor Paper Weight Explained (Find Out What’s Best) first appeared on Watercolor Affair.

I’ve found myself in this situation a few times. The important question being whether there’s a “correct side of the paper on which you are intended to paint.

So what side of your watercolor paper should you use? Most of the time the answer seems to be “whichever side you like”. The only real difference being a subtle variation in texture. But with that being said, there IS a difference between the two sides of the paper. And this difference varies depending on the brand and type of paper you choose to paint on.

I did a little research to find out what changes you can expect between one side of your paper and the other!

What Side of Watercolor Paper to Use

If you’re asking yourself this question then it probably means there isn’t a huge visual difference between the two sides of your paper. This is true for the majority of good quality 100% cotton papers on the market. The only noticeable difference is a slight change in texture between the two faces.

Of course, the real question we’re asking ourselves is whether there’s a discrepancy in the handling qualities of the “front” and “back” of the sheet.

The two factors which might have an influence on how the paper handles (apart from your choice of weight, surface finish, etc.), are the “tooth” or textural variations and any possible differences in the sizing of the paper sheet.

Differences between handmade and moldmade watercolor paper

100% cotton paper can either be handmade or moldmade.

To begin with, cotton fibers are mixed with a large amount of water to make paper pulp.

Handmade papers are produced using a rectangular hand-held mold. This is basically a big flat sieve with a wire mesh stretched across a frame. This mold is dipped into a vat of cotton pulp, then sloshed around to spread the pulp evenly over the mesh. The water drains away and the pulp sticks to the wire mesh.

This sheet of pulp is then transferred to a sheet of felt for drying. This wet paper sheet is sandwiched between successive layers of felt (like a big paper and felt lasagna). A big press is used to squeeze out the water and begin the drying process.

​I’m telling you this so you understand the difference between the two sides of traditionally made watercolor paper. As you have probably guessed, this process can produce two different surfaces to the paper.

The first is the wire side where the pulp adhered to the mold.

And the second is the felt side where the sheet was placed on the felt for drying.

Of course, both sides end up getting squeezed between sheets of felt, which reduces the difference in texture between the “front” and “back” faces. But the impression left by the wire mesh often persists. And the two sides of the paper are referred to as the wire side or the felt side.

With handmade papers this generally means you get a more important difference in surface texture on each side.

For a better idea of how this handmade process works take a look at this quick video which shows the handmade process of Fabriano paper:

​Now, handmade papers are pretty expensive (they are more labour intensive than machine made papers). So most of us stick to professional quality 100% cotton paper which is made by machine. This type of paper is what we call moldmade.

Moldmade paper relies on the same method as handmade paper, but to make things easier, the whole process is automated. The sheets of watercolor paper are fabricated as one continuous very long sheet. To do this the wire mesh is in the form of a cylinder mold. This cylinder is dipped into a vat of paper pulp and rotated so that the pulp slowly adheres to the surface of the wire mesh.

The wet sheet of pulp then gets transferred to a sheet of felt, and sandwiched between felts to begin the drying process.

​This manufacturing process results in paper which has a less conspicuous change in texture on each face of the sheet.

So you can compare the two processes, here’s another video, this time showing Fabriano’s moldmade paper production:

So Which Side of your Watercolor Paper do You Use?

Okay… So what can we take away from all this?

The only real difference for most of us will be a slightly different surface finish on the felt side and the wire side of the sheet. Depending on the brand of your paper and the production method used, this variation in texture will be more or less pronounced.

I suggest you experiment to find out which side you prefer.

​Personally I use Arches paper for my finished paintings (here’s the stuff I buy at Blicks). The difference on cold press paper is very subtle indeed, but over time I’ve come to recognize each side, and I use the “front” sheet as it is presented to me when I open the pad or block.

A quick tip if you buy large sheets and cut them up. Use a pencil to mark the “back” of the sheets with a “B” so you can quickly determine which side is which!

As for sizing, there should be very little divergence between the two faces. In fact, Arches boasts that it is one of the few brands which sizes its paper with gelatine “to the core”

Can you Paint on Both Sides of Watercolor Paper?

By now I’m sure you’ve guessed the answer is yes. It really is a question of personal preference. I’ve found very little difference on both faces of Arches, Winsor & Newton, and Sunders Waterford papers.

I often use both sides for sketching. You get double the value out of each sheet!

Related reading: Best paper for watercolor painting

The post Which Side of Watercolor Paper to Use (Complete Guide) first appeared on Watercolor Affair.

You lay down a nice watery wash of paint, you settle down to enjoy your painting, and then… It all goes lopsided ! 

When watercolor paper absorbs liquid, it buckles and deforms, leaving ridges and depressions which make paint flow difficult to control. It’s a nuisance which all watercolor artists have to deal with. This is pretty annoying because as you continue to paint, pigment tends to run into the low valleys and settle in pools.

Ultimately this affects the appearance of the finished work.

I used to think that simply by using watercolor paper you could avoid this problem.

But even watercolor paper expands when it becomes wet.

Yep… Even though watercolor paper is designed to accept water based medium and is quite stable, it still warps because of wetness.

This is especially true if you add a lot of wet watercolor washes or pre-wet the paper for a wet on wet technique.

So how do you avoid this pesky problem ?

Stretching your paper is the common solution. But I’ve found there are a few different ways to do this. Indeed, some watercolor artists invent ingenious ways to prepare their paper. Each method has its own advantages and drawbacks.

So I thought I’d put together this article to show you 3 different ways for stretching your paper and 1 common example of how NOT to stretch watercolor paper. Plus as a bonus, I’ll even suggest how you can avoid stretching paper altogether !

Why do you have to stretch watercolor paper?

Primarily we stretch watercolor paper to avoid “cockling”. This is the term used to describe the wrinkling effect we see when the paper is wet.

Good quality watercolor paper is made from 100% cotton fibers. The method used to manufacture commercial paper causes the paper fibers to align in the same direction.

When the paper fibers absorb water they expand lengthwise, and they take on a more random alignment. When the paper dries, the fibers contract again. But to some extent the fibers retain their irregular alignment. This change in the structure of the fibers is what causes raised ridges and low valleys to form on the surface of the paper which we see as buckling.

So stretching is designed to eliminate the problem of cockling.

But there’s also another interesting and useful consequence of paper stretching.

Commercial watercolor paper is also treated to alter its absorbency and improve its handling. This is done by adding a chemical known as sizing.

Untreated paper is like blotting paper and has a very high rate of absorption. Sizing is designed to help control this characteristic so that all of your paint doesn’t get sucked up by the paper !

But sometimes watercolor paper can have irregularities in the surface sizing.

If the absorbency of the surface is not regular this can cause blotches when you apply a wash of color.

The methods used to stretch paper help to dissolve some of the sizing, creating a better distribution of sizing across the paper and a more receptive surface.

Dissolving the sizing is an incidental result of soaking the paper during the stretching process, but it’s also common for some artists to brush their watercolor paper with clear water before working to eliminate the problem of blotchy sizing.

How to stretch watercolor paper

Whichever method you choose to stretch your paper, the basic approach is the same: first you soak the paper, then you stretch it.

When you soak the paper it expands. You then fix the edges of the paper so that when it dries and contracts the surface is pulled tight like a drum. When you begin a painting session your paper is pre-stretched and it won’t warp or crumple. You now have a perfectly flat surface while you work.

Soaking the paper

You begin by wetting the paper. For this most artists opt for one of the following methods. Soaking with a spray bottle, sponge, or large brush. Or immersing the sheet in a tub of water. Lukewarm water seems to help the paper expand more quickly.

Spraying the paper rather than immersing it takes a little more time.

If your using a sponge or bristle brush, be careful not to wipe over the sheet too firmly, as this will raise the fibers on the surface and can damage the paper.

If you’re soaking in a tub, simply plunge the sheet into your water container. If the sheet doesn’t fit completely, dip one end into the water and drag the paper through the water from one end to another repeatedly.

If you opt for the spray or brush technique, you can place your paper on a clean board, soak it, then turn the paper over and soak again. Repeat the process until the paper is fully soaked.

Personally, I prefer the immersion method because there is less chance that you damage the paper.

How long do you need to soak watercolor paper ?

You need to soak your paper just the right amount of time or you can run into problems later. If you soak too much, the paper expands considerably. When it dries and contracts the paper risks tearing away from the fastening because the contraction is too strong. On the other hand if you don’t soak enough, the paper will dry flat and taut, but when you add watercolor washes it may still buckle.

About 5 to 10 minutes of soaking is usually about all you need. I use Arches watercolor paper most of the time and I find this is sufficient. (Its important to use good quality paper. Arches is one of the best brands. You can read more about the best type of watercolor paper here).

I recommend you do some testing if you use a different brand.

You’ll get a feeling for when to stop soaking the paper, when it turns limp and starts to behave like cloth. The paper loses its springiness when it’s sufficiently dampened. Test the “spring” by folding a corner from time to time to see if the paper is fully soaked.

The thickness of the paper will affect the amount of time needed for soaking a sheet. The average time for soaking with 300 gsm paper is at least 5 minutes. Heavier papers require more soaking time and lighter papers need less time.

Don’t soak too long because you don’t want to dissolve all of the sizing. This treatment is added to improve the performance of the watercolor paper. If you soak too long the internal sizing will wash away.

Stretching the paper

To stretch the paper you need to fasten the soaked sheet to a smooth flat rigid surface. It’s good to use a board which is at least 1” larger on all sides than your sheet of paper. This leaves room for taping the paper to the board.

Lay the soaked paper onto your chosen support and if needed, make sure it’s flat by chasing out any air pockets using a clean sponge. Make sure you put the paper the right way up ! If you’re using single sheets you can tell which is the front side by looking at the watermark. Orient the sheet so that the watermark reads correctly.

The paper will “stick” to the surface when its wet so try to position it correctly the first time, otherwise it can be tricky to move around.

Some good materials to use for stretching boards include:

Marine grade plywood (A good choice if you prefer something solid. Make sure the surface is smooth and consider painting it with an acrylic primer to make the surface less porous. ½” is a good minimum thickness).

Gator foam board (stronger than normal foam board, but still just as light, and with an impermeable surface).

Plexiglass (stable, lightweight and adds the advantage of transparency).

Canvas frame or stretcher bars (lightweight and cheap).

There a different ways to fasten the paper down to the board or frame. The most common is using gummed tape which is easily available. Another popular method is with staples, but I recommend you use a heavy duty stapler.

How long does it take for watercolor paper to dry?

Try to leave the paper in a warm dry place to dry overnight. 24 hours is a good average but you should test the paper to check if it still seems cold or damp before using it.

Some watercolor artists stretch their papers in advance and store them on stretching boards, so they are ready for use.

Make sure you leave the board flat while drying, and not upright. If you stand it vertically, the moisture will run to the bottom and may cause the gummed tape to pull away from the board.

A lot of artists will warn you against using a hairdryer to dry the paper.

In reality this seems to depend on the method you use for stretching, but also how well the paper is fastened down. In general the paper needs to dry at the same rate all over and your paper should not be soaked for too long.

A bit of patience pays off !

4 Ways to prepare watercolor paper:

1 – Completely soak and tape with gummed tape

This is probably the most common method. Here I’m using a marine ply board but you can use gator board with this technique. Just make sure your board is clean and won’t transfer color to the paper and is rigid.

Soak the paper using one of the methods described above.

To fix the soaked paper you need some gummed tape. This kind of tape is water activated. You just need to wipe the glue side of the tape with a wet sponge to activate the glue. Be careful not to wash the glue off by rubbing or wetting too much.

If you’re a perfectionist you can draw some pencil guidelines about a ¼” around the inside edges of your paper. This will help align the gummed tape precisely.

Gummed tape is a better option than masking tape. Gummed tape will stretch with the paper but masking tape will not. Be careful not to drip glue from the gummed tape onto your paper, the glue will dry and cause blotchy marks when you paint.

Tape the paper down on all four sides, starting with two opposite sides. For example left and right, then top and bottom. Check for air bubbles while taping.

This kind of fixing is good most of the time, but to be safe it’s a good idea to add some staples to reinforce the fixing. The paper shrinks and tries to pull away from the taped edge. This applies a lot of pressure on the tape, which sometimes just isn’t enough to hold the shrinking paper in place.

Lay the board flat to dry. To remove your painting cut around the edges of the sheet using a sharp craft knife. If you try to remove the gum tape you risk ripping the painting !

2 – Stretching on a canvas frame

I’ve seen a lot of artists use this method which results in a nice tight paper surface. It’s a technique I first learned from the artist Ewa Karpinska.

For this method you need an empty canvas frame or canvas stretcher bars. You can either get hold of some cheap frames and strip the canvas, or buy stretcher bars and make your own frames.

Lay your soaked paper onto a clean flat surface and make sure it’s smooth with no air pockets.

Place the canvas frame in the center of the sheet and wrap the paper around the back edge of the frame.

I recommend you use a heavy duty stapler to fix the paper in place, it just makes the job easier. Start by stapling in the middle of each side, and work your way around. The corners should be folded neatly, and stapled in place.

Leave flat to dry. The final result is beautifully smooth and a pleasure to work on.

3 – Using a watercolor paper stretcher ​

The final method is to use a specially designed paper stretching board. The system was originally invented by the British watercolor artist Ken Bromley. He called it the “perfect paper stretcher”.

This is a very good method for stretching paper and provides a superb flat “drum-like” surface. The board has grooves around the edges. You use rubber strips to secure the soaked paper in place. You may need to use a hammer to force the rubber back in place, which adds a good amount of additional tension. Some artists recommend putting candle wax into the grooves beforehand so that paper removal is easier.

And because the paper is so firmly held in place you can also use a hairdryer to speed up the drying process !

Pretty cool…

How NOT to stretch watercolor paper

This is a technique which some artists refer to as quick and easy. The whole process is done directly on the board and with less water, so it’s a bit less messy.

I’ve seen artists show this method and to be honest i had my doubts, so i thought I would test it before passing judgement.

Tape your paper down to a board and use masking tape to fix the paper in place.. Make sure there’s no air trapped under the paper.

Now wet the paper using clear water and a large soft brush. Go over the paper a couple of times to make sure the whole surface is dampened.

Finally dry the paper using a hairdryer !

This method is simple and you can use the paper soon after preparation. So it would be a good method if you’re in a hurry.

But in my tests this method does not work !

Taping the paper with masking tape before soaking defeats the purpose completely. The paper expands when wet, then when blow dried it seems to go back to a flat surface. But when you paint on the paper even with a medium wet wash, the paper buckles anyway !

Feel free to give it a go, but frankly I wouldn’t recommend this technique. This is not what I call paper stretching.

Pre stretched watercolor paper

I see a few artists claiming that watercolor blocks are pre-stretched.

Watercolor blocks are a stack of sheets that are bound together with thick adhesive around all four sides. Block papers are not stretched. However they do seem to resist warping better than loose sheets.

I find that watercolor blocks still buckle when painting with heavy washes, but the paper flattens when it dries. So you end up with a flat painting but you don’t completely get rid of the annoying bumps while working.

Blocks can however be very practical for plein air work.

What’s the alternative to stretching paper ?

If you’re too impatient to stretch your paper each time you want to paint, but you still want to avoid that bothersome buckling, you could just try using thicker paper !

Like a lot of watercolorists, I use Arches watercolor paper for a lot of my work.

But did you know they make thick watercolor paper with a weight of 300 lb / 640 gsm?

This type of paper is so heavy that it only buckles slightly after repeated wet washes. 640 gsm paper is thick enough to resist warping even for wet on wet techniques.

This is almost like cardboard ! And on top of that you can get this paper in block format. So you get some of the benefits of a watercolor block (which helps to hold the surface flat) and a lower amount of buckling because of the thickness of the paper !

Not a bad option !

Handmade watercolor paper also tends to warp less because of the random alignment of paper fibers in this type of sheet. Handmade air dried sheets tend to cockle less and in random way which is evenly distributed over the whole sheet. But  if you can get very thick handmade paper this is an excellent surface which needs no stretching.

How to flatten a watercolor painting

Oops !

So you didn’t stretch your paper and now your painting is all wonky ?

Not to worry. There are ways that you can try to recover a painting which has buckled after a painting session.

The simplest method for flattening wonly watercolors is as follows:

1. Dampen the back of the watercolor painting using a water spray bottle.

2. Sandwich the painting between two sheets of clean paper.

3. Place the painting on a flat surface and cover with a board of some sort.

4. Now place weights on top of the board (some heavy books will do the job). The board will help distribute the weight across the paper surface but try to spread the weights out evenly.

5. Leave for at least 6 hours to dry.

Some people use an iron to flatten buckled paintings. Be very careful if you try this method because there’s a real risk that you’ll burn the paper, so use a low heat setting. Moisten the back of the paper first then iron the back of the painting, with a towel placed on top for protection.

Conclusion

If you can’t stand buckling, try preparing your sheets of watercolor paper in advance. Personally, I like the board stretching method using a plexiglass sheet so I can transfer my drawings, or the lightweight advantage of using stretcher frames.

Stretch paper only when necessary and when it suits your painting preferences.

If you reached the end of this long article, congratulations !

Now go have a good stretch ! 

The post 4 ways to stretch watercolor paper first appeared on Watercolor Affair.

It’s one of the essential components in watercolor painting. And believe me, when you really get going, you’re going to use a lot of it !

I remember when I started watercolor painting, I went to a huge art store near to where I live. They had an amazing choice of watercolor paper. All kinds of different sizes and formats.

The choice was mind-boggling !

So I asked the store assistant for help.

But when she asked me “do you want cold press or hot press” ? I have to admit I was stuck.

So What is the difference between hot and cold press watercolor paper?

In a nutshell, the terms “hot press” and “cold press” refer to the paper’s surface finish or texture. Cold pressed paper has a slightly bumpy, textured surface. But hot pressed paper has a smooth surface finish.

You will also hear artists talking about the tooth of the paper. For example, hot press paper has almost no tooth, but cold press paper has a more pronounced tooth.

Why should you care what kind of paper you use ?

Watercolor paper is a little more complicated than just “rough or smooth”.

It would be a mistake to attach little importance to your choice of paper. It actually has an effect on the results you obtain when painting, and different types of paper will react differently to paint.

There’s only one way to find out which type of paper suits you best, and that is to experiment.

With that being said, understanding the different characteristics of watercolor paper will go a long way to help you choose your paper confidently.

What are the differences between cold press ​and hot press watercolor paper ?

Cold press ​paper characteristics:

Cold press watercolor paper is labelled CP (or in england NOT meaning not hot pressed).

The term “cold press” originates from the process used to manufacture the paper.

A sheet of paper is basically a thin mat of tangled cellulose fibers. To make cold pressed paper, sheets of cellulose pulp are pressed through felt covered metal rollers at cold temperature – hence the designation “cold press”. The felt rollers and the drying process used contribute to the bumpy texture of this type of paper.

This is probably the most popular type of watercolor paper.

It’s known to be relatively easy to use, and is well adapted to almost any style of watercolor painting – hence it’s popularity.

Cold press paper is more absorbent than hot press. This means you have slightly less time to move the paint around the surface before the pigments fix to the paper.

Colors are less rich and slightly paler when using cold press paper. This is probably due to the way light reflects off the paper (after all, the white paper is the source of light for a watercolor painting). The indentations on the bumpy surface of cold pressed paper scatter reflected light, thus producing softer diffused colors.

This type of paper is ​dimensionally stable when wet.

It also accepts a certain amount of corrections or lifting off (where you remove some of the paint pigments off the paper).

The texture of the paper itself adds to the aesthetic appeal of the final painting.

Paint pigments settle and dry in the grooves and less on the ridges of the paper, revealing the texture of the paper, and contributing to the appearance of the finished artwork.

​Hot press ​paper characteristics:

Hot presswatercolor paper is labeled as HP.

Again, the term “hot press” refers to the method of fabrication used for this type of watercolor paper. Traditionally, with this method, the sheets are pressed at high pressure between smooth heated rollers – hence “hot pressed”.

This technique also contributes to the smooth surface finish of the paper.

This type of paper is popular for precise styles of watercolor work because it’s good at showing a high level of brush detail. This paper is also well adapted to styles that want to accentuate the watery irregularities of the paint and for combining pen and ink with watercolor. This makes the paper good for glazing (successive layers of dried paint) although when there are many layers of paint the surface can get overloaded quickly. This type of paper tends not to hold the pigment in place as ​well as cold pressed.

Because of the higher density of the paper fibers, hot press paper is less absorbent giving you more time to play with the paint before it dries.

Pigment colors are more vivid with hot press paper, probably because light is reflected directly off the flat white surface of the paper, producing brighter colors.

Lifting off paint is easy with this type of paper even when dry.

​A quick comparison between hot and cold press paper

Hot press paper:

• ​smooth surface finish
• ​colors are brighter
• ​less absorbent
• ​more time to play with the paint
• ​good for precise brush detail
• ​lifting off and corrections are easy

Cold press paper:

• ​textured bumpy surface
• ​colors are more flat
• ​more absorbent
• ​slightly less time to play with the paint
• ​good for all styles of watercolor painting
• ​tolerates some lifting off and corrections

​​The quality of watercolor paper

There are some other important factors you need to keep in mind to help you judge the quality of the watercolor paper you choose. The quality of the paper affects the way that paint handles on the surface and the smoothness of your brush strokes.

A paper’s quality is dependent on its composition and the manufacturing process used to make it.

​As mentioned earlier, paper is made up of cellulose fibers. Today, the more common sources of cellulose are wood, cotton and linen, with wood pulp being the most used.

However, wood is not a good source of cellulose for watercolor paper.

The biggest threat to a paper’s durability is acid. Acidic papers such as those made from wood pulp can become brittle and discolor in a very short time.

Wood cellulose causes acidification over time so wood pulp papers should generally be avoided for artistic use.

Cotton fibers are strong and flexible and they are naturally white and acid free. Cotton cellulose is also up to 10 times stronger than wood cellulose.

This makes cotton an ideal substance for watercolor artist grade paper.

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​How is watercolor paper made?

The manufacturing process used also affects the quality of the paper. As you can imagine, mass produced automated paper production is is less expensive and lower quality than handmade watercolor paper.

​Handmade watercolor paper

This is the highest quality manufacturing process and the strongest type of paper.

The strength comes from the fabrication process. The mold used for making paper by hand has two parts – a wooden frame with a wire mesh stretched across it (the mold) and a second frame placed on top of the mold (called a deckle).

The mold is basically like a big sieve which is dipped into a vat of cellulose pulp. The mold is then moved up and down and side to side. This hand spreading results in the paper fibers being completely interlaced, making the final paper very strong.

The deckle is then placed on top of the mold. This keeps the wet pulp within the bounds of the wire mold and helps control the finished size of the paper sheet.

Handmade watercolor paper is recognisable by it deckle edges which are result of this paper making process. You can tell handmade paper because all four sides of the paper have a deckled effect.

Note that some manufacturers add deckle edges to industrially made papers. This is known as a faux deckle edge.

Moldmade watercolor paper

Moldmade paper is the next best quality manufacturing method.

With this type of method, the wire mesh is in the form of a cylinder which turns at slow speed. The pulp is poured over the mesh and the sheet of pulp is deposited onto a moving belt of felt.

With this method the the cellulose fibers a fairly randomly interwoven resulting in reasonably good paper strength.

Moldmade paper is recognisable by it’s two deckle edges(the very long sheets produced by the machine are cut into individual sheets leaving two cut edges and two deckle edges).

Machinemade watercolor paper

This is the lowest quality production method. Cellulose pulp is injected into a machine which has a wire mesh sheet, then sandwiched between two layers of felt. These machines produce a continuous roll of paper at very high speed.

With this process the cellulose fibers are not very well interlaced and tend to be aligned in one direction, resulting in paper which has less strength.

What is the GSM of watercolor paper?

As you probably know, watercolor paper is available in different thicknesses. Thickness is indicated by the weight of the paper. The weight is labeled as gsm or g/m2 or lb.

GSM refers to grams per square meter and is a more recent and more accurate measure of the weight and thickness of watercolor paper. You will also often see an imperial measurement equivalent in lb or pounds per ream.

My advice is to stick to GSM when comparing paper and forget the traditional pounds per ream measurement.

The thickness of watercolor paper is important because it has an influence on how much the paper buckles when wet and how quickly water is absorbed and dries.

Thicknesses can vary from one brand to another, but the more common weights are as below:

• ​Thin – 190 gsm / 90 lb
• ​Medium – 300 gsm / 140 lb
• ​Thick – 356 gsm / 260 lb
• ​Board – 640 gsm / 300 lb

​​​What’s the ideal paper for watercolor painting?

It’s up to you to find which paper suits you best, but if you stick to the following guidelines you should be OK !

The ideal weight for watercolor paper seems to be 300 gsm. Anything lighter will buckle easily when wet, and can tear when using a wet on wet technique. Thicker paper also tends to absorb quicker and modify the water cycle when working wet on wet. Using thicker paper means you can avoid having to stretch the paper to prevent it from buckling. However, the thicker the paper, the more expensive it becomes !

Remember to use 100% cotton, acid free paper for your final paintings. It’s fine to use lower grade papers mixed with wood cellulose, for anything else.

Most watercolor paper is moldmade, so the quality is good. If the paper is machinemade, that’s fine – but you should probably reserve this kind of paper for sketchbooks and watercolor studies. From time to time I like to buy some handmade paper for the sheer pleasure of it !

You’ll find a complete review of watercolor paper here…

​What are you waiting for ? Go use some watercolor paper !

Of course paper is ​just one of the basic​ necessities for painting – read more about which supplies you need for the best watercolor experience.

The post Cold Press vs Hot Press watercolor paper – Here’s how to choose ! first appeared on Watercolor Affair.