I recently ran into a problem I hadn’t experienced before while working on a small gouache painting: the paint cracked as it dried.
I was painting a light green object over a dark background. The background was painted with HIMI gouache, while I used Winsor & Newton gouache for the object. Because gouache can reactivate when it gets wet, I was concerned that adding too much water to the lighter paint would pick up the dark color underneath.
My solution was to use the Winsor & Newton gouache fairly thickly to get the opacity and clean edges I wanted.
It worked while the paint was wet. By the next morning, however, the light green areas had developed a network of fine cracks.
Why Did My Gouache Crack?
Traditional gouache can crack when it is applied too thickly. Gouache dries to a matte paint film, and a heavy layer can become brittle as it dries and contracts.
In my case, I also added more paint in areas where the first strokes didn’t give me the smooth coverage or clean edges I wanted. That created an even thicker layer in some places.
The result was a good reminder that more paint isn’t always the best way to get better coverage with gouache.
What I’ll Do Differently Next Time
For my next attempt, I plan to use just enough water to give the gouache a smooth, creamy consistency while keeping it opaque. If the first coat doesn’t provide complete coverage, I’ll let it dry before applying another thin layer instead of continuing to build up wet paint.
I’ll also avoid painting the dark background underneath areas that I know will eventually be a much lighter color. Leaving some of the white watercolor paper exposed should make it easier to achieve an opaque light color without using such a heavy layer of paint.
Can Cracked Gouache Be Fixed?
For now, I’m leaving the cracked paint alone. Adding water could reactivate the gouache and potentially loosen or disturb the already cracked surface.
Once the painting is finished, I’ll check whether the paint is stable before deciding what to do next. I already plan to repaint this particular piece, but I may keep the cracked version too. Sometimes a painting that doesn’t go as planned can still be useful, especially when it teaches you something for the next one.
If you’re learning to work with gouache too, you can also read my post, Does Gouache Reactivate With Water?, where I share more of what I’ve learned about layering and working with this medium.