Watercolour paper is a versatile surface which has a degree of absorbency that allows transparent colour to appear its most luminous. Watercolour paper is not only for use with watercolour paints – it can also be used for acrylics, gouache, pastels, pencils, graphite, charcoal, and it can also be primed for oil. With many options that are 100% cotton, it can make a durable and archival support for many different mediums. If you’re unfamiliar with any of the watercolour paper terms, click on the underlined words to read the definition.
Everything You Need to Know About Watercolour Paper
Contents
What is Watercolour Paper Made of?
Why Does Paper Buckle When Wet?
How to Stretch Watercolour Paper
Is There a Correct Side to Work on Watercolour Paper?
Watercolour Paper Comparison Table
What is Watercolour Paper Made of?
The pulp that watercolour paper is composed of determines its strength, abrasion resistance, longevity, and price.
Acid-free Wood Pulp
The most affordable watercolour papers, as well as those found in many watercolour sketchbooks, are made with wood pulp that has had naturally occurring acidic components, like lignin, removed. As a result, these papers resist discolouration and yellowing, but they are not as durable as cotton papers.
Cotton Linters
Cotton linters are the purest source of cellulose and their fibres are longer than in wood-free pulp, making a durable paper that can take heavy treatment. Most 100% cotton watercolour papers are made using cotton linters.
A Blend of Acid-free Wood Pulp and Cotton Linters
A percentage of cotton linters in these papers adds strength and durability, while being more affordable than 100% cotton watercolour paper.
Cotton Rag
Cotton rag papers are made with recycled cotton textiles. Cotton textiles are made using the longest fibres from the cotton plant, so cotton rags make even stronger paper than cotton linters alone. Cotton rags are mechanically beaten in such a way as to maintain this long fibre length.
Cotton and Linen Rag Blend
In addition to cotton rag, some papermakers add recycled linen cloth to their papers. Linen is derived from flax and is even stronger than cotton. Its long, thin fibres interlock with the cotton fibres, adding even more durability.
Left: Jackson’s Eco Paper, 100% cotton rag
Right: Jackson’s Two Rivers, cotton and linen rag blend
Texture
Hot pressed paper has the least textured surface, having been pressed between hot metal rollers during production. Hot pressed paper is favoured by those who like to work delicately with a lot of detail, such as botanical artists. Hot pressed paper tends to be the least absorbent of all of the textures, and watery washes can sit on the surface for a long time. Beyond watercolour painting, hot pressed watercolour paper makes an excellent support for detailed pen, ink and graphite drawing.
Cold pressed (NOT) paper is made by pressing the sheet through cold metal rollers, and it has a slight texture to it. It is the most popular watercolour paper surface to work on because it is well adapted to many painting approaches. The paint will sink a little into the dimples on the surface of the paper, but it will also be sympathetic to some more detailed work. Cold pressed paper tends to be a little more absorbent than hot pressed paper.
Rough paper is the roughest texture paper available, it is pressed between sheets of textured felt during the drying process and is not pressed between smooth rollers. The heavier texture means that granulating effects are enhanced. This paper surface is suited to bold, expressive painting techniques.
While hot pressed, NOT, and rough are used almost universally by watercolour paper manufacturers to describe the texture of their papers, the actual surface textures vary greatly between manufacturers, or even between batches (particularly with handmade papers).
Left: Granulating pigment on rough watercolour paper
Right: Hot pressed, cold pressed (NOT), and rough watercolour paper (left to right)
Colour
Because watercolour paint is transparent the colour of the paper, even different shades of white, will affect everything on top of it in both the painted and unpainted areas. The colour of 100% cotton watercolour papers vary depending on whether it is tub sized or not (external gelatine sizing will impart a slight brownish tinge), the purity of the water used in production, and the raw materials used for manufacture. Many 100% cotton papers are an off-white colour which is often referred to as ‘traditional’ white. Some ranges have a separate line of ‘extra-white’ or ‘high-white’ alongside their traditional white papers.
Optical brightening agents, or OBAs, can be added to the pulp during production to make the paper whiter and brighter. These brightening agents are prone to deteriorating over time, which can cause a colour shift in the artwork as the paper fades to off-white. Because of this, makers of archival standard watercolour papers avoid the use of optical brightening agents and add a lightfast white pigment, like titanium dioxide, instead. While lightfast extra-white watercolour paper is noticeably whiter than traditional white papers, they are not as white as optically brightened paper. This is because there is a limit to the amount of pigment that can be added to the stock without compromising the bonding strength between the paper fibres.
Similarly to extra-white watercolour papers, tinted and black watercolour papers, such as Bockingford Tinted and Stonehenge Aqua Black, are made by adding lightfast pigments to the stock. Khadi Handmade Black watercolour paper is made using black cotton rags. However, because the dyes used in the rags are not lightfast, the paper is prone to fading, particularly if exposed to sunlight.
From left to right: Stonehenge Aqua Black, Somerset Black Velvet, Khadi Handmade Black, Royal Talens Van Gogh Black.
Watercolour Paper Sizing
Watercolour paper should be absorbent enough to stabilise the paint, but not so absorbent that the colour becomes dull. Sizing provides a little water resistance, so that the paint does not sink too much into the paper, and partially sits on the surface. Watercolour paper can be sized internally, externally, or both, with gelatine, starch, or a synthetic size like Alkyl Ketene Dimer. Internal sizing is when the size is added to the water and pulp mixture before the paper has been made. External sizing (also known as tub sizing) is when the formed sheets of paper are pulled through a gelatine bath. Some papers are both externally and internally sized which increases the wet strength of the paper. Papers that are externally and internally sized are usually best for masking fluid.
All watercolour paper manufacturers size their paper differently. A wash of semi-dilute paint, without any attempt to work it into the paper, is a good test to see how a watercolour paper is sized. Watercolour papers that have been treated with a lot of size have a high resistance to water and are known as hard-sized papers. On them, dilute washes of paint will want to sit on top of the surface or even bead up. Another sign of a hard-sized paper is a feathery ‘tide mark’ around the edges of the wash, created as the paint sits on the surface and the pigment migrates to the edges. Hard-sized paper has higher abrasion resistance, and tends to withstand more vigorous painting techniques, like scrubbing and reworking of the paint. It is also ideal for lifting techniques because the colour does not penetrate the fibres of the paper and is more easily removed (depending on how staining the pigment is).
The ‘feathery’ effect of very hard sizing
Watercolour papers that are less heavily sized (sometimes called soft-sized papers) are less resistant to water. The paint will be absorbed more readily into the paper which makes it ideal for techniques like glazing, where transparent layers of paint are applied on top of previous layers of colour. Soft-sized watercolour papers might have a softer surface texture. Sheets of handmade papers are individually sized by hand, so the sizing can vary from sheet to sheet. This is part of the character of the paper and can enhance the enjoyment of working on it. Synthetic and gelatine size is broken down by detergents present in soap, household cleaning products and even brush cleaner. Even a small amount can cause the paper to become extremely absorbent, behaving like blotting paper. If soaking watercolour paper, it’s best to do so in a dedicated tray rather than in the bath or a sink. If using a bath or a sink then it’s important to ensure that all soap residue is removed. Brushes should also be thoroughly rinsed after using brush cleaner.
Why Does Paper Buckle When Wet?
Buckling occurs because paper fibres expand when wet. If you use very little water in your technique, then very little buckling will occur, if any. For more watery applications a heavier weight paper (425gsm and above) will buckle less.
Buckling watercolour paper
Stretching watercolour paper involves deliberately saturating the paper with water in order to expand it, fixing it to a board, usually with gumstrip around the edges, then allowing it to dry before painting. Preparing your paper like this is the best way to ensure a completely flat surface.
How to Stretch Watercolour Paper
What you will need:
- A clean, soap-free tray of water, with one dimension slightly longer than the shortest edge of your sheet of paper or, if you don’t have a tray, a clean spray bottle.
- A clean, soap-free sponge or paper towel.
- A rigid board – plywood or plastic is ideal.
- 4 strips of gummed tape, to glue each edge of your paper to the board. It helps to pre-cut each length so that it is 3cm longer than each edge.
The most common and inexpensive method of stretching paper is to begin by soaking it in clean water for a few minutes (140lb weight paper will need up to 8 minutes, heavier paper may need more). If your sheet of paper does not fit in the tray you can hold it at opposite edges and feed it through the tray multiple times to ensure the whole sheet is soaked.
Soaking watercolour paper
Lift the sheet from the tray and allow any excess water to drain from it before placing it flat on your board. If you do not have a tray simply place your paper on to the board you wish to stretch it on to, and spray generously on both sides of the paper with clean water. Try to only touch the paper on its edges as it’s possible to leave visible finger marks on the stretched paper. Sponge off the excess water gently with a clean sponge – the outward motion you use to do this will help flatten the paper onto the board. Once you feel that the paper is adequately stretched out, wet your gumstrip using a clean paintbrush or sponge, but do not immerse it in the tray of water for too long as this can wash away too much of the adhesive, and it may not be able to hold the paper in place as it shrinks.
Wetting gumstrip before using it to stretch the paper
Place the gumstrip tape on the edges of the paper so that half the width is covering the paper’s edge, and half is stuck to the board. When doing this, take care not to let water from the tape drip onto the paper, as this will leave spots on the paper when you start to paint on it. Use a dry paper towel to press the tape down, which will also soak up any excess water. Lay the board flat and allow it to dry (it may need to be left for a few hours, or overnight to be completely dry) before you start your painting.
Taping watercolour paper to the board
When your painting is finished, leave it to dry completely before cutting the paper free from the board using a sharp craft knife. You can remove gumstrip from the paper by soaking it with a sponge to rewet it, and then carefully lift it off with a palette knife or craft knife.
Is There a Correct Side to Work on Watercolour Paper?
Cylinder mould-made watercolour paper has two sides which vary slightly in texture. The felt side is the side which is formed in contact with the woollen felts and usually has a more irregular texture than the mould side, which is formed in contact with the wire mesh. Both sides of the paper are pressed between felts (in the case of rough and cold pressed papers), or between hot metal rollers (for hot pressed papers) later on during production, which evens out much of the difference between the two sides. If the paper is watermarked, you can identify the felt side by holding the paper up to the light and finding the side from which the watermark reads correctly.
Left: The Saunders Waterford watermark
Right: The cylinder mould that forms the watermark
Pads, blocks, and packs of cylinder mould-made paper are generally presented with the felt side up. However, because the paper is evenly sized on both sides, they are equally suitable for painting on. We recommend inspecting and feeling the texture on both sides of the paper before you start painting to see which one you prefer. Handmade paper is pressed between back to back felts and the texture is the same on either side. The slightest differences in texture may occur from sheet to sheet. Either side can be used.
What is a Deckle Edge?
A deckle edge is an irregular edge to the paper (as opposed to a clean edge) found on many handmade and cylinder mould-made papers. The edge is formed when some of the wet pulp goes beyond the frame of the mould.
A diagram of a handheld mould used to make handmade watercolour paper
Because handmade rag papers are individually formed, they are the only papers that have four true deckle edges. Cylinder mould-made watercolour papers only have two true deckle edges, and often the two remaining edges are torn with a specialist knife, or cut with a water-jet to create pseudo deckle edges. In the 19th century, deckled edges were seen to be imperfections in the papermaking process, and would be trimmed. Today, however, many artists find a deckle edge pleasing to the eye and like to frame their work in such a way that keeps the deckle edges on show.
Left: Pseudo deckle-edge on cylinder mould-made paper
Right: Genuine deckle edge on handmade watercolour paper
Watercolour Paper Comparison Table
Our table compares the content, texture, sizing, colour and surface strength of artist watercolour papers. Click the image below to enlarge, or download our PDF version here to print.
Further Reading
Everything You Need to Know About Drawing Paper
A Guide to Watercolour Painting
On Location at the Two Rivers Paper Mill
Thank you! An interesting article article and a useful paper comparison table! This helps me to select a paper equivalent to my usual paper, if that happens to be out of stock. And of course it gives me ideas for papers I want to try…..Thank you very much.
So glad you found it helpful, thanks Jane!
Thank you for the great watercolor
information. But I am only working in
oils just now, between standing &
sitting. a struggle at 92plus, but
somehow I keep going.
Hallo! How do you preserve the original
deckled edges after stretching the
paper? I mean when you tape down all 4
sides of a sheet and finish a painting,
how can I bring the true deckled edges
back?
Hi! Thanks for your comment. Once you’ve cut the paper away from the board you can remove gumstrip from the paper by soaking it with a sponge to reactivate the adhesive, and then carefully lift it off. Alternatively, you can use a heavyweight paper (425gsm and above, or 600gsm if you use a lot of water in your technique) which would resist buckling and wouldn’t need stretching- then you don’t need to risk damaging the paper removing the tape.
Thank you!
I’m just starting out in lino printing and
would really appreciate a similar article
on printing papers.
Our Paper Guide contains an article comparing printmaking papers that you might find useful!
very useful. please could you post a high resolution photo of both felt and mold sides of saunders waterford paper an also of the wire/ mesh to help me recognise each side? thanks you
Hi Fawzia
Thanks for your comment, that is a good suggestion! I have contacted our photography team to see if this is something we can do.
Many thanks
Lisa
Great article containing valuable
information. Thanks, Evie and Jacksons for
providing the info.
Thanks for your lovely comment Rene!
Informative, thanks!
I would just like to thank you for such
interesting newsletters, I have found
them to be very useful.
That’s great to hear, thank you Stella!
Hi Evie, thank you for a great article. I
wanted to ask what is the best tape to use
on watercolour paper as I tape up my
watercolour paper and paint within the
square. I sometimes get paint bleed, tearing
and glue escaping from the tape when I am
using a wet on wet technique. What is the
best tape you can recommend? Thank you,
Peter.
Dear Peter,
Thanks for your question, I am responding on Evie’s behalf. I want to make sure I understand your question – are you peeling the tape away after painting? The conventional gumstrip tape often used for watercolour painting is not designed to be peeled away. When you use it to fix your paper to a board for paper stretching the idea is to cut the painting out from the board once dry. If you wish to peel the tape away to get a clean white border surrounding your work, you will need to use masking tape. To minimise the risk of the paint spreading underneath the tape, make sure you smoth it down evenly by rubbing your finger along the edge, and try not to apply brush strokes that direct toward the edge of the tape – try to brush away if you can. Leave the tape on until your painting is completely dry, and then, when peeling the tape, peel it away slowly, and pull the tape so your hand is up against the tape that is still stuck to the painting. If you have your hand raised and your pulling the tape at ninety degrees from the painting it is likely to tear the paper. Also it is worth remembering that masking tape develops a stronger bond the longer it is applied to a surface, so don’t leave it on for longer than you need as it will become harder to peel away. I hope that makes sense and answers your question, but feel free to get back in touch if you have any further questions.
Link to masking tape: https://www.jacksonsart.com/search/?q=masking+tape
Best wishes
Lisa
Very informative, thank you. The table
is great, especially for comparing
options within my favourite brand
Thank you Sue, so glad it’s helpful to you!
Very very informative article, specialy
for self made artist. So much impress,
thank you sooo much.
Thank you so much for the valuable
information on water colour papers. Your
article has helped me to resolve my
issues related in selecting the paper for
water colour paintings. I should really
appreciate efforts put in by you for
preparing the comparison table.
It’s great to know you found it helpful, thank you!
Thanks so much for this article. It
explains everything about paper very
well and I understand so much more
now.
Cheers Kathy, glad you found this piece helpful.
A very helpful article, and thank you for the terrific chart.
One wee suggestion for your techies would be to add
“material” (e.g. 100% cotton, cotton/pulp mix, etc) to the
shop’s search function for paper. Thanks!
Hi Beth,
That is an excellent suggestion, I’m amazed we don’t have this already. I’ll pass it on to the people developing the new site!
Best wishes
Lisa
Thank you for the information I’m a
crafter not an artist, but still like to know
about the products I am using and how
to get the best results , this article is
great thanks again .
Glad it was helpful to you! Thanks for reading!
Very good article. Love the photo with all the
paper ingredients and characteristics!
Thanks for letting us know Edo, we’re glad you enjoyed it!
What is the origin of the term ‘sizing’ in
watercolor paper? Why is the gelatin added
called ‘sizing’?
Hi Marla
Size, sizing, and glue-size are all words used for the sealant substance that is 1. added to paper pulp (a chemical powder not like gelatine at all that is used to coat the fibres, called internal sizing), 2. applied on top of a sheet a paper (a liquid similar to a weak gelatine solution, called external sizing), 3. used to seal the surface of canvas from oil paint penetration, 4. used to seal wood so it is less absorbent for painting techniques, 5. used to glue gold leaf down, and lots of other formulations and applications.
Like many words in English, it sounds like another common word and this can cause confusion. If someone says “he was holding a bat”, you don’t know if it was a cricket bat or a small flying mammal, except in context of the rest of the conversation.
I found this for the etymolgy of the word:
From Middle English syse,[1] of unclear origin;[2] related to Old Italian sisa (“a glue used by painters”),[3] perhaps ultimately related to size / syse (“amount”),[2][3] or perhaps shortened from assisa, from assiso (“to make to sit, to seat, to place”)
Noun
size (plural sizes)
– A thin, weak glue used as primer for paper or canvas intended to be painted upon.
– Wallpaper paste.
– The thickened crust on coagulated blood.
– Any viscous substance, such as gilder’s varnish.
By the way, it’s not usual these days for the external size on paper to be gelatine, now most paper manufacturers use a non-animal derived substitute.
Great Article! I noticed that
Winsor&Newton Pro watercolor paper
doesn’t have gelatine. Is it the new ones
with the blue cover or the grey one. W&N
does listing the sizing (except for saying
optimum sizing) on there website
Hi Rajiv, the Winsor and Newton professional watercolour paper is the one with the blue paint on the cover