Watercolor paper comes in various weights and the lighter variants can buckle (also known as cockling) when they get wet. How can I prevent or reduce this from happening? Is there a preferred technique or should I just buy the really heavy paper?

  • You can't prevent it from buckling when it gets wet, but you can take measures for it to dry again flat.
    – Earthliŋ
    Apr 27, 2016 at 0:37
  • 1
    @Earthliŋ - Not that I think that's entirely true, actually, but I would suggest posting some of those measures as an answer. Something about cotton and irons comes to mind...
    – Joanne C
    Apr 27, 2016 at 3:47
  • Well, ironing your paper isn't a preventative measure...
    – Earthliŋ
    Apr 27, 2016 at 10:48

3 Answers 3


To prevent the paper buckling/cockling you pre-stretch it, That is you wet the paper and tape it down to a rigid board with gum strip. I generally use a wooden drawing board that I made in work shop practice 50 odd years ago. Note masking tape does not work as well as gum-strip for this as it does not adhere very well to wet paper.

You paint onto the stretched paper and only cut it free from the gum-strip when finished.

Heavier paper (say 300+ grams per square meter) usually does not cockle when you paint on it using water colour technique (do not regard this as a challenge, I'm sure you could get it to cockle with a wet enough technique).


When paper gets wet, it expands. Apply wet watercolour to only part of the paper, and only part of the paper will expand, causing the paper to buckle. If there are no constraints on the paper, the paper will dry buckled.

(This effect will be less noticeable the thicker the paper is.)

Before you paint

You can purchase blocks of paper where every page is attached to the sides, and thus stretches the paper while it dries, causing it to dry pretty flat.

You can achieve the same effect (although less effective) by taping loose sheets to a board with masking tape.

Another method is to immerse the paper (should be at least about 180 g/m²) in water completely before painting. This way the paper expands uniformly in all directions and dries pretty flat as well.

After you paint

Sandwich your paper face down between two layers of cotton fabric and steam-iron your paper (in all directions). Put a board and some weights (heavy books) on to dry. If you look to frame your painting, you will probably want to do this step, regardless how flat the paper dried with the above methods.

  • After we wet the paper by immersing it in water, we will have to wait for it to diy before we start painting. Then will it not start buckling again? Apr 27, 2016 at 13:31
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    @TheIndependentAquarius No, you paint on it while it's wet. Of course this is a different technique (wet on wet).
    – Earthliŋ
    Apr 27, 2016 at 13:38
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    @TheIndependentAquarius - When stretching paper for watercolor work, you do usually let it dry first. It's the drying action that helps prevent buckling and it requires you to really tape it down with the right kind of tape. Needless to say, I knew that, but I was giving a window for others to answer.
    – Joanne C
    Apr 28, 2016 at 3:25

At one time there was a mixture called sizing made from scrapings of still wet rabbit skins the inside of the skins.

You would wet the paper with water first then tape it down to a board with a heavy tape like duct tape then brush it down with sizing. Once the paper dries, brush it down with sizing again, allow it to dry, then size it one more time allowing it to fully dry.

You should be able to cut the paper then and be able to paint on it without fear of it buckling.

  • Hi Calvin! To use duct tape sounds like a terrible idea, as it is too strong and will ruin the paper: have you tried it yourself? And what is the benefit of using size over water?
    – Joachim
    Jun 13, 2021 at 19:40
  • @Joachim, re: tape, the answer describes cutting the paper away similar to the accepted answer. An obvious difference with sizing is that you would be painting on a dry surface, which would have a different effect (e.g., less bleeding) than painting on damp paper.
    – fixer1234
    Jun 13, 2021 at 20:27
  • @fixer1234 It's not mentioned in the answer indeed, but usually one would wait for the paper to dry, also when using water. It will then stretch itself perfectly flat again (if taped properly). But, yes, with size you can easily transport the paper, so this would indeed be very convenient when painting outside, for example.
    – Joachim
    Jun 13, 2021 at 21:38

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