Varnishing artwork is the final step in protecting it before it goes up on the wall. To seal a gouache painting we must consider it’s natural tendency to reactivate when moisture is added. Therefore to protect a gouache painting we have limited options.
After lots of research, I found one product that I absolutely love!
Sealing Gouache Paintings with Cold Wax Medium
I’ve tried using spray fixative with disappointing results. The spray fixatives I tried dulled the painting or didn’t create a waterproof seal. So for a long time I gave up and framed my gouache under glass. However recently I’ve started painting on panels which will be hung in floater frames, so glass is not an option! I needed something that would withstand moisture.
Enter: Dorland’s Wax Medium. See below to watch my video showing the test results of pouring water onto my sealed painting.
Tips for applying cold wax medium to gouache
- Make sure the gouache painting is 100% dry!
- Use a soft cotton pad (like the kind you find in the makeup isle), a soft tissue, or a soft clean cotton rag.
- Use enough to get a smooth resistant-free motion (you don’t want to scrub the surface of the gouache with a dry towel). When using the right amount, it glides effortlessly over the painting.
- Don’t use too much though, avoid chunks or uneven application.
- Let dry for at least 3 hours before applying another coat.
- You can spot-test with a drop of water on the dry seal to see if you want to add another layer.
- When done properly, the water will bead up on the surface and can be wiped away without disturbing the gouache.
Does sealing with wax medium change how the gouache looks?
Yes, a little. The colors will be deepened slightly and the values reduce a tiny bit. This can be good or bad, depending on your painting! I found that it gave my paintings a “richness” that I liked. Also, the protective quality makes it totally worth it in my opinion.
Researching How to Seal a Gouache Painting
As I mentioned, I did quite a bit of digging around online to find something I wanted to try (without ordering a ton of different products). At first, I was scared away by the idea by Winsor & Newton’s opinion on the subject.
Varnishing a gouache painting should be avoided, because the varnish drastically affects the depth, darkness and finish of the work. And should anyone want to retouch the painting again at some point in the future, perhaps for restoration purposes, the varnish will not come off.
Winsor and newton’s website
Yikes! But I continued on, sure that there must be an alternative to glass. I found lots of random forum posts, and videos.
Finally, I stumbled upon this blog post about comparing wax mediums and was so thankful for their in-depth testing and research, because it led me to buying Dorland’s Wax Medium, and I love the results! I’m looking forward to trying it mixed with oil paint – but that’s a topic for another day.
You can hear my thoughts and watch my test here:
This post is not sponsored. However if you would like to support the Fearless Brush, you can purchase Dorland’s Wax Medium using my affiliate link and I get a tiny commission towards buying art supplies. Thank you!
I’ve been enjoying your very informative posts and videos today…thank you for sharing! I’ve never used gouache, but am considering using it instead of oils for quick travel sketches. I have two questions regarding using the wax medium to protect gouache paintings: First, can you ever go back and paint further (with gouache) after sealing with the wax medium? Secondly, if you hung a wax-sealed painting in a home and direct sunlight hit the painting, would that cause a problem of the wax melting? Or would the wax have been absorbed into the gouache surface? Thanks, Sarah, for your help! …and I love your work! š
Thank you! Gouache doesn’t like to adhere to anything solid, slick, or basically non-porous so I can’t imagine it would stick to wax. And yes if you heat the wax it will soften, so if you hang it direct sun I’m sure you’d have issues.
Thank you this demo. Iām curious if after the wax medium dries over the gouache, would a soft gel medium adhere to the surface? I want to collage over the base gouache painting. Thanks for your advice
Alan Lidji
I’m not sure, I haven’t tried that – but if you buff the wax down so it’s not “thick” or textured, it is VERY matte, and I have a feeling anything would stick to it.
You could always do a small test piece, but it might be like trying to apply acrylic over oil.