Most watercolour painters have experienced the frustration of their paper buckling causing the paint to flow everywhere except where they want it to go. Stretching watercolour paper makes it stay flat for the whole painting process. The experience of painting on watercolour paper that stays perfectly taut and flat is a revelation to painters who have always fought with their paper.
If you have wanted to stretch your watercolour paper but thought it was too hard or too time-consuming this might help you see that it is pretty simple. If you have tried but been unsuccessful this might help you see the few simple rules that will lead to successful stretching.
An even wash of blue is ruined by the swelling areas causing the colour to pool in a valley, creating an unintended line of paint.
An even wash on this paper stretched with staples stays even and doesn’t pool
because the paper stays flat
Stretching Watercolour Paper
Why stretch watercolour paper?
Watercolour paper that is less than 200lb (425gsm) will cockle when it is wet, forming hills and troughs that make it impossible to control the flow of watercolour. Stretching paper involves soaking the paper until it swells, attaching it to a rigid surface and allowing it to dry until it shrinks and becomes taut (or painting right away if you wish to paint wet-into-wet). The taut surface allows you the freedom to paint without battling against the puddles of colour, using as much water as you like.
Boards
Cut your paper about 3cm larger on each side than you wish your finished painting to be, you will lose this amount of paper from the area covered by tape.
Your board should be at least 3cm larger in all directions than the paper you will be stretching.
You will need a strong board that won’t warp under tension. I’ve had good results with both the Jackson’s Wood Boards and Jackson’s Smooth Panels, both used in this article.
Jackson’s Smooth Panels also work great.
If you have old paper tape stuck to the surface, remove it before you stretch. This is easily done by wetting the area with a sponge and scraping the tape off with a palette knife or razor.
Gumstrip Tape
Cut gummed paper tape in advance, 3cm longer than each side, set aside and keep dry (don’t let it get splashed at all). I keep the tape in a plastic bag.
Prepare your gumstrip tape strips in advance and keep them dry.
Soaking
Soak for 5-10 minutes for 140lb paper, more for heavier paper. Each make of paper will be different. You will know that the paper has soaked enough when it feels floppy like wet cloth. You want it to absorb all the water that it can, but if you soak it for much longer it may start to lose its sizing. Watercolour paper has a sizing added (gelatine or gelatine substitute) that keeps it from being too absorbent. If it were as absorbent as blotting paper your paint would sink down inside and not sit brightly on top. If you soak your paper for too long you may remove the sizing on the surface and make your paper too absorbent.
Soak large sheets in a bathtub that has been well cleaned as soap residue can cause spotting on your paper. Soak smaller sheets in a large flat plastic tub. If you have no way to immerse your paper you can wet it with a sponge and keep wetting it and turning it over, but this method will take up to 5 times as long for the paper to become fully wetted.
Immerse a smaller sheet in a flat tub of water to soak.
Taping
Wet the wooden board evenly.
Remove the paper from the water and hold by one corner to allow much of the water to drip away. Take your paper to your wet board. Bow the paper in half to create a gentle roll in the centre and line this centre up with the centre of your board. Lower the paper and drop it, centre first. You do not need to rub it down, it will lay itself well against the board. If it doesn’t land in the centre pick it up and bow it and try again. If you have large air pockets raise just that corner and release them, but small air pockets will not matter. Wet your prepared strips of tape with a sponge, but do not wet so much that you wash away the gum. I use a small sponge that I squeeze most of the water out of, in one hand I pinch the tape and sponge together and then pull the tape through. Your tape should not be dripping. Then, holding the tape evenly over the whole length lower the tape strip all at once to the edge of the paper, half on the paper and half on the board. Gently run your fingers around the edge to make sure all the air bubbles are removed but trying not to stretch the tape.
Caution: If the tape looks like it is not sticking well do not be tempted to run a wet sponge over the top of the tape as this will ensure that your tape fails, it seems to remove the glue.
Remove the paper from the water by one corner and shake to see if it feels floppy like wet cloth. Then allow much of the water to drip away.
Bow the paper in half to create a gentle roll in the centre and line this centre up with the centre of your board.
Lower the paper and drop it, centre first.
You do not need to rub it down, it will lay itself well against the board.
I use a small sponge that I squeeze most of the water out of, in one hand I pinch the tape and sponge together and then pull the tape through.
Holding the tape evenly over the whole length lower the tape strip all at once to the edge of the paper, half on the paper and half on the board
If the tape looks like it is not sticking well do not be tempted to run a wet sponge over the top of the tape as this will insure that your tape fails.
Caution – Tape Dripping
Be sure not to drip water from your tape onto your paper as this will leave spots on your paper where the paint will not stick. (You may have noticed spots on your paper in the past and thought the paper was faulty.)
Gummed tape drips that were invisible on the paper show up when you start to paint.
The gum drips act as a resist and spots show up under the paint.
Drying
Leave to dry completely, probably overnight or a day. This is the only downside – you need to prepare your stretched boards ahead of time. You can blot the whole surface pressing with a gentle downward motion (no rubbing!) using a folded bath towel or pile of kitchen roll, being very careful not to shift the tape at all. Dry your board flat, not tilted on its side which would make it dry unevenly as the water runs to one end, unless you rotate the board around every 5 minutes or so. It can also pool water under your tape and remove the glue. Speeding drying with a hairdryer causes the same problem, uneven drying. You want even tension, so no area will pull loose. So be patient.
During this process, your paper has swollen and grown larger by a few millimetres. As it dries it is shrinking back to its original size and pulling on the tape. If you use a hairdryer and cause one area to dry faster it will shrink and pull loose the tape of the part that is still damp. The success of paper stretching is a result of the right amount of water and even drying. With practice you will figure out how wet you need your board to be and how wet you need the tape to be and the best way to ensure even drying.
Dry flat, do not rush it, be patient.
After you have painted – and your painting is dry
Let your painting to dry on the board.
To remove the dry painting from the board you will want to pierce the tape and slide a knife around your painting to leave half the tape on the board and half on your painting. You can cut along the edge of the paper and lift it off the board. Most artists leave the tape on the painting as it will be hidden under the mount when you frame the painting and wetting the tape to remove the adhering tape might damage the artwork. The tape edge also adds stability. White acid-free tape is available if the brown bothers you. And archival gummed tape is safest for leaving on your paper.
Simply cut along the edge of the paper and lift it off the board
Attaching with Staples
Another option is to staple your soaked paper to the board. It is faster and not prone to the tape failure caused by too much or too little water or stretching or shifting of the tape when applying. It also leaves marks but they can be nearer the border so you lose less paper. It is a good choice if the board you have is the same size as your paper, not allowing the border needed for the tape. The only drawback is that it seems to hold the paper less tautly, but it is so much better than unstretched paper and is foolproof. I used an office stapler with good results. A staple remover saves sore fingers when you come to remove your dried finished painting.
Another option is to staple your soaked paper to the board.
Paper Stretcher
An alternative to using gummed paper tape or staples is to use a paper stretcher.
Paper stretchers use clamps to hold the soaked paper to a board. These come in specific sizes and your paper must be trimmed to fit, a few mm less than the board so that it is not larger than the board when soaked, as the paper swells. These work well, although they don’t save any time because attaching the clamp bars takes the same amount of time as applying the tape. A benefit is that there is no tape on the border, though there is a crimped edge to the paper. A drawback is that you must use the size of paper required.
Trim your paper to about 5mm smaller on two sides than your board. Soak as usual and drop on the board. This is a little more fiddly as you don’t have room for error because there is no border.
Then attach and tighten the clamp bars.
After the paper is dry and after you have painted and the painting is dry then remove the clamps. Notice the crimped edge of the border that will need to be hidden under a mountboard. Your clamps will probably need a wash before you use them again as paint can get inside and might cause problems with your next painting.
Alternatives
- If you wish to avoid stretching watercolour paper but you wish your surface to remain flat you can use heavyweight paper, over 200lb, or watercolour board (watercolour paper laminated to board similar to mountboard).
- If your style of painting uses very little water you will have less cockling and might get away without stretching your paper.
Heavyweight paper and watercolour board do not need stretching
If you use very little water you will have less cockling
If you master the simple art of stretching watercolour paper you will find it takes little time and makes a huge difference to your painting experience. Many artists prepare a few boards at the same time to work on more than one painting at a time or to not have to wait to paint again until the last one has dried and been removed from the board.
Click on the underlined link to go to the Watercolour Paper Department on the Jackson’s Art Supplies website.
Postage on orders shipped standard to mainland UK addresses is free for orders of £39.
That seems unnecessarily complicated, and over wet., risking washing the size off the paper ..and the gum off the tape…
I lay dry paper on a board, wet it with a wash of clean water with a 3 inch wide soft chinese brush, leave for a minute and then tape the top edge and stand the board upright on the floor for a couple of minutes, the excess water drains off and the weight of the wetted paper stretches it down a little. Then tapes the sides from top taped edge to bottom smoothing the tape downwards. Then tape the bottom edge, it should dry in an hour. Quicker in the sun.
This has worked for me for 30 years
Hi Jenny
Whatever works for you is perfect. Each artist has a different painting style and uses different papers.
Thank s for sharing your simple method, it sounds great.
I have tried it many ways and found this one worked best for me. If the paper isn’t fully saturated and expanded I got cockling during painting, perhaps because I use a lot of water during painting. Yes, I am quite concerned about sizing as well and am careful not to over-soak it.
Can you explain please why running a damp sponge over the tape once in place will cause failure
I use your stretching method, but I do press the tape in place with my sponge. Additionally I the place a clean thin plastic table mat across the Middle (leaving the edges exposed) add a book for weight, then put my next board on top etc until I have a pagoda of boards stretching paper.
I find keeping the middle damper for longer in this way ensures success. But I am interested to understand what’s behind my question above. Thanks
Hi Susan
It’s interesting that it doesn’t cause problems for you.
Over the years and in the recent tests I did to write the article, I found that 100% of the time this caused my tape to lose all of its glue so as it dried it came away completely.
I don’t know if it is wiping away the glue or if the times I do this are when it already looks like it has a problem of not sticking, like I have used too much water so it has already washed away the glue. Since it looks like it is not sticking I give it another wipe but it doesn’t help, only makes it worse by adding more water.
Your flat matt to slow drying sounds like an interesting idea. It sounds like it makes sure the tape is dry before the paper starts pulling on it. Thanks for sharing it.
Whatever works for you with the tape is great, it seems everyone does it a little differently, or a few people do it a lot differently. This was just one way.
I find that wiping the glue side of the tape with a wet sponge is what “guarantees failure”, because it makes it *too* wet and removes glue. I use the sponge to wipe excess water off the paper onto the edge of the board, lay down the *dry* tape, and if necessary wipe the back of the tape with the sponge. This always works well (for me, anyway) because the glue cannot be lost.
I simply use a fine mist bottle to apply the correct
amount of moisture to my butchers tape !
I soak my paper in a sink or bath for around 20 – 30
minutes.
My boards all receive a border of at least 2″ – 3″ of
marine grade varnish to facilitate adhesion and removal
tape if required.
Works every time even on full sized sheets.
Hi Jim, I don’t know if you’ll read this
all these 4 years later but if you do…
can you please tell me what kind of
wood you use? I’m trying to find some
that I can have cut up into various
sizes without actually buying them
from an art store because they always
seem much more expensive that way,
especially if you want multiples. So
I’m trying to find out what type of
wood is used to make these boards.
Thank you, Angela
Hi Angela
In case Jim doesn’t still get notified of your comment –
The key is to get wood that will not flex when a lot of pressure is applied. As the paper dries it shrinks and that is what makes it nice and taut to work on. But that is a surprising amount of tension and it will cause thin wood or thick card to bow. Plywood is the usual choice as it is designed to resist bowing and marine-grade plywood or a few coats of varnish will make it ok to use with water. I think 6mm is the thinnest most people use.
Let’s see if Jim is still around to add to this.
Can you stretch 300 gm paper more than once if you
end up with a wrinkle
Hi Hugh
Good question! Yes you can but you have to be aware that each time you soak your paper you will inevitably lose some of the sizing and the paper will end up more absorbent. So we suggest you don’t soak the paper for as long second time around.
Many thanks
Lisa
Does the wood board need to be acid-free?
Can acids from the board leach into the
paper during the stretching process?
Hi Liz,
If you’re stretching the paper, painting and then removing it relatively quickly then boards such as MDF (which are held together with acidic PVA) won’t really have a chance to cause damage to your paper. If you’re likely to keep it on the board for weeks on end then yes, it’s best to use an acid free board – in which case it’s best to also make sure you store the board somewhere where it is not in direct sunlight and away from humidity or extreme temperatures.
Some places such as cities with a lot of traffic have a higher degree of acidity in the atmosphere…there are times you cannot escape it! The key is to try and minimise the contact of materials with acidity with your art materials if you want to maximise their longevity.
Many thanks
Lisa
Should you expect to see any bubbles in the
drying process? Can anything be done about
them, once on the board, if not?
Hi Gregory
I would restretch it if it has bubbles after it is dry.
To prevent them in the future – if you let the paper fall to the board from the centre out, as shown in the article, it should push any bubbles out as it falls.
But then inspect it and if you see a bubble release it by lifting that corner of the paper. If you can’t remove them or there are too many then lift the paper and try again.
I hope that helps.
I add color to printed title pages and
fancy printed initial chapter letters of
books I print. I have no problem if the
the title page has a small border or if
the initial letters are small, say 2”x2”
but I have problems if the borders and
initial letters are large. Is there any kind
of paper on which I could print but
would not coccle when painted? Would
acrylic paint be better?
Hi Joe
Are you using watercolour?
Acrylic gouache looks similar but is very matt and opaque and it dries waterproof. But it still takes water to use it so it might also cockle the paper.
Cockling is usually most affected by the weight of the paper, thicker paper can absorb the amount of water used in the paint without swelling as much as a thin paper which is overwhelmed by the water. If you could print on thicker paper and use less water in your paint that should help. What kind of paper are you using now?
How do you remove tape from paper if you
don’t want it under the mat? I prefer seeing
the edge of paper.
Hi Lyna
Gummed paper tape is not designed to be removed and is usually hidden under a mat. To be less obvious some people use white gumstrip. But that still needs to be hidden.
The alternatives to tape are stapling to the board or using a paper stretcher. Both of which leave marks on the paper.
If you wish to frame your painting floated so the edge is visible, my best suggestion would be to use very heavyweight paper. A very thick paper will not cockle much with water and if it has a deckled edge – like Jackson’s Two Rivers or Khadi paper – it is quite beautiful.
Using less water when you paint or flattening the work under weights after it is dry are other possibilities if you don’t want to stretch your watercolour paper.
Hi Lyna
I have heard of watercolour painters that stretch their paper as usual and then apply masking tape to cover the inside edge of the paper in a small border, just inside the gumstrip. They then paint, let it dry, cut it off the board and then can trim the gumstrip tape off the paper and still have a small white border for framing. So just don’t paint to the edge of the gumstrip tape and you can cut it off without worries.
I hope that helps.
I have ironed paintings between a
clean sheet of paper, on the image
side, and a clean towel, on top. I use a
hot iron on steam setting, and mist
the towel so it’s slightly damp. Then, I
put a ton of weight on top and leave it
overnight to dry. That seems to
flatten paintings that have buckled…
Thanks Kathy, that is a great method!
the paper stretcher shown much better than
anything else I’ve tried. Leaves marks but
paper stays flat. Have 1/2 and 1/4 imperial I
bought in UK 30 odd years ago still using.
Please tell me you have a supplier as hate
using gummed tape.
Hi Tony
We don’t have the paper stretcher shown anymore, it was a low-price model and didn’t keep the paper as tight as our professional one the Keba.
You can find it on our website here:
Keba Paper Stretcher.I was taught stretching paper by my arts
teacher. For now i had always done it one
a board i had lying around.
Although this time i fucked up. I used a
bigger paper than i usually used. And my
board being too thin, it warped. Causing
my paper to warp as soon as i started on
the background.
What to do now? Just throw it in the
trash? :/
Hi Sylvie
The paper drying pulls much more than you would think. If it has pulled the board out of shape, then you are right the board is not strong enough.
Sounds like you need to start over with a heavier board that can withstand the tension.
I’m new to water coloring. I’ve done what
you suggest except I used a sponge to
wipe the brown tape and it failed. Had no
idea until I read this that it could have
been my wiping that caused it to fail.
This last time I stapled and taped. So far
so good. But what puzzles me is that I
let my painting dry 5 days and then I
took it off the board and within 5 minute
so the Arches 140 lb cold press paper
had buckling and twisting. Do I need to
do something else so that a finished and
dried watercolor painting stays flat?
Hi Luann
I’m sorry but I don’t know why it buckled after you removed it, it should have remained flat. Did you let it soak long enough to swell up? Did you let it fall naturally to the board or did you push it? Did the tape hold it in place or did it move?
There are ways that artists use to flatten a warped painting.
You can lay the painting face down on clean paper, lightly mist water onto the back, and then do one of two things: either put a cloth over it and iron it on medium heat or put clean absorbent paper on the back and lay weights like books on top to flatten it for a few days. Please let me know if either of these work for you.
Thank you. I’ll give it a try and see
what works.
Hi. Firstly, why haven’t I found these
articles before? How will I find them
again once I’ve forgotten where it is?
Great tips, thanks. I’ve really been
struggling with my tape coming loose
from the board- now I know I’ve been
getting it too wet!
Stretching paper tomorrow, will make
sure not to wet too much.
Also will try your way of letting centre of
paper down first.
I need more boards, but your links in the
post don’t take me to them. Hard to find
stuff on Jackson’s web site.
Thanks again.
Hi Jim
I’m glad you find them useful!
You can bookmark the blog of course or you can always find the link in the footer of the Jackson’s website.
I looked at the article and saw that the links to the boards were broken, so I have fixed that. Here is a link to the boards: https://www.jacksonsart.com/jacksons-wooden-sketching-board
I’m sorry to hear that you have trouble finding things. We have so many products that it is hard to sort through them all. We work really hard to make it so that you can search with words or browse by department and then filter down to just what you need using the filters on the side. But it isn’t perfect. We are working on a new website that should launch early next year and we hope it will be an improvement.
Hi Julie, I was given a board for stretching
my watercolour paper. Where the paint has
gone over the tape on to the board, it has
caused the grain to slightly rise. Should I
varnish the board? It is a plywood –
specifically made for drawing.
Hi Justine
It does sound like the board is reacting to the water. And yes, sealing it will help with that.
Did the wood also react to the wet area under the paper?
Hi
Once I have stretched the paper and it is
fully dry, is there any reason why I
cannot remove the paper from the board,
and repeat the process to build up a
supply of ready to use paper?
I can then just tape it to the board when
I’m ready to paint,
Or do I need to paint before I remove it
from the board ?
Thanks
Hi Mike,
You need to paint on the paper and allow it to dry before you remove it from the board. Stretching the paper on the board keeps the paper taut while you paint. If you were to remove it and paint on the paper loose then it would just warp. A watercolour block is a pad of paper glued on all 4 sides which keeps the paper taut while you paint, negating the need to stretch paper. If you want to save time and don’t need to paint on a large scale this could be of interest to you: https://www.jacksonsart.com/surface/paper-card/blocks
Many thanks
Lisa
Hi! Can I fully wet stretched with the tape paper and work like wet-on-wet?
Thanks!
Hi Natalia,
Once the paper has been stretched to the board and has dried, you can then rewet the painting and work wet-into-wet, but oversaturating the area where the tape is may cause it to move. That said, getting it a bit wet would not cause any problems. The paper will expand as it absorbs water, and then shrink again as it dries, with the tape holding it taut and ensuring the paper stays flat when dry.
Hope this helps
Lisa
Thanks a lot! I’ll try!
I used to get 100pct success with my old gummed tape using the method described above. But the new tape is, for me, hopeless … one side or another fails to fix. I think the old tape used fish glue and the new is starch glue and not much of it. So I suspect it’s the subtlety of wetting the glue just enough but not too much which is the key. Ah well … try again k suppose! Cheers D
Hi Diederik,
How do you wet the gumstrip? I’m wondering whether some of the glue is washing away. A rung-out, damp sponge can moisten the tape to just the right degree.
Many thanks
Lisa
Mam,
Thanks for the detailed describtion. May I
use your blog content as an educational
resource and material, please?
I will definitely acknowledge the reference.
Hello Majid.
Of course you can, I’m glad you find it useful.
But yes, please do acknowledge us.
Additionally, are you aware of our affiliate scheme? Our affiliates add links to our products on their website and earn a 5% commission on any transaction that has come through the link. Furthermore, the first time a customer uses your link they get 10% off their first order.
If you are interested you can sign up here or find out more about the scheme on our blog.
Hi Julie,
I’m getting ready to paint a large scale
watercolor, 3 feet x 4 feet and was
wondering if you know the easiest way
to stretch it? Aside from buying 300 lb
paper (which is almost impossible to
find at that size!) I’m thinking of buying
a piece of plywood and stapling it to that
to stretch it. Now, am I able to remove it
after it’s stretched so I don’t have to
have the plywood around me? I would
like to remove it off the plywood and
tape it onto a large piece of plexiglass.
Do you think it will still buckle if I do
that?
Hi Alicia
Stretching is the act of affixing the paper to a surface while it is wet (and so swollen a little) so that when it dries (and shrinks a little) it is tight on that surface.
As soon as you have removed it from the surface, it’s just paper again, it is no longer stretched.
If you use gumstrip tape to affix your soaked wet paper to the plexi it might stick well enough to use as a stretching board. But if it is bendy at all then it will bow with the tension caused by the paper shrinking as it dries. So it would need to be a thick, rigid piece of plastic.
Hi Julie,
This is very helpful, thank you so
much for your help!
You’re very welcome!
Hi, I’ve been stretching paper and all is well until I come to remove it. Its tearing and sticking to the board. Any tips or ideas why
Hi Beth
Let your painting dry taped on the board. To remove the dry painting from the board you will want to pierce the tape and slide a knife around your painting to leave half the tape on the board and half on your painting, cutting along the edge of the paper and lifting it off the board. There is a photo of this in the article.
You then leave the tape on the edge of the paper and hide it under the framing mount. You can use white tape instead of brown. or trim the paper to cut off the tape. There should be no tearing because you do not take the tape off the paper.
The tape that is left on the board can be soaked and scraped off with a paint scraper.
Hi, I bought the Jackson’s : Lightweight
Drawing Board with Metal Edge for my
watercolor stretching board. After I received
it, I applied two layers of Gesso to seal it
from warping. Do you think it will do the job?
or you have better option to seal the board
surface? Thanks
Hi Fiona
That drawing board doesn’t need any treatment to prevent warping, it is a good stable surface.
You might find problems with the gesso when it gets wet from the paper, or it might be fine. If you have problems just sand the gesso back.
I have a bubble in my tape where it didn’t
fully stick once dry. Can you suggest a
remedy?
You could try putting some water in the gap and pressing down. or put some masking tape over the gap, if that is the concern. If you can paint with the bubble there is should be fine.