Can you rehydrate dried gouache?

This is a question that comes up pretty often. Can you rehydrate dried gouache? Is it worth the effort? The answer to both of these questions is yes, it’s worth the effort if you want to save your paint.

How fast dries the gouache paint on the palette?

The thinner the paint is on the palette, the faster it will dry. Depending on the weather, it can dry in 15 mn or less. The thicker the paint is on the palette, the slower it will dry.

If you’re painting in Plein air, the direct sun may get your gouache paint dry in a couple of minutes on your palette. 

How to rehydrate gouache paint?

If you rehydrate your dry paint on your palette, you’ll never get back the initial creamy consistency. And if you do manage to reconstitute some gouache in this way, it will never be as smooth as when it was first opened.

Once the paint is dry on the palette, you can add water with an eyedropper or a brush onto individual dried spots. Rub the paint surface with your wet brush, and you’ll lift pigments. If you have a lot of paint on your palette, you can use your brush to add water. Gently tap the tip of your brush into a water container and add it to the paint. Don’t pour or splash water onto the surface; this will cause pigment particles to disperse into tiny dots and mix the colors.

The liquid paint you’ll get is excellent for backgrounds and the first layers in a painting. But as it’s not creamy, it’s less opaque and unsuitable for final layers and details.

How to prevent gouache from drying on the palette?

To avoid your paint from drying and having to rehydrate it, you can prevent it from drying:

• use an airtight palette, close it and store it in the fridge between painting sessions
• use a Stay-wet palette to keep the paint hydrated
• squeeze your paint on a wet cloth taped to the palette
• squeeze small amounts of paint at a time to limit waste
• spray your palette with tap water to hydrate the paint and prevent drying. I can spray 4 or 5 times during a painting session to keep the paint fresh. 

Rehydrating gouache on a finished painting.

To rehydrate the paint and blur edges, use a brush wetted with clean water and dab gently over the desired area. You can also use your wet finger to rub the ‘border’ between two colors and merge them. 

The downside of the re-wettable gouache is that you can drop water on it and get a stain. To avoid this, protect the finished parts with a sheet of paper when painting.

And when the painting is finished, you may want to protect it with a varnish. 

Conclusion

The best way to rehydrate gouache is to avoid it drying out in the first place. Use the tips from this article to prevent your gouache from drying, and if you want more gouache tips, you can get my ’60 gouache tips’ free cheat sheet.