MITRA Forum Question Details

I think that gouache on true gesso or chalk-glue ground sounds like a fine choice as long as it is not applied too thickly. I would not overly smooth the ground (like one does for egg tempera) to provide a bit of mechanical tooth.

I would only varnish watercolor or gouache paintings if you want the aesthetic change that it causes. Really only glazing will provide the protection you are interested in. The next thing that I can think of is to frame the work in a deep shadow frame to help prevent physical contact.

Gouache can shrink upon drying over a wooden or hardboard panel to the point where cracking and crazing can occur, especially when the priming swells or re-wets from taking up water. In my experience, a paper-faced support is better for gouache. 

I can confirm, as Brian stated, that varnish will dramatically change the appearance of gouache. Color depth and value contrast are increased to the point that what was subtle becomes extreme, and mid-tones become extremely dark. Varnish does not, however, afford sufficient protection to prevent re-wetting from accidental contact with droplets or a damp cloth, so the finished art still needs protection in the form of glazing.

Matthew

Thanks for weighing in. I have seen the same phenomenon you describe on paper and cardboard supports when the gouache is applied thickly. I was thinking that it would fine on panel in a similar manner as other water borne media as long as the paint is not too thick. Thanks for the correction.

I didn't mean to contradict you, Brian. I just happen to have become an "instant expert" on gouache crazing on a primed panel when I spent way too long on a nice little painting that ended up spoiled. It looked amazing and was really nice to work on until the paint failed. There might be a way to modify the gouache so it retains a tiny measure of flexibility, but I didn't experiment further.​

It is not a big deal about the texture of the ground in this case since its absorption should provide enough of a bond, again as long as the paint is not applied too thickly. I have not encountered the issue that Michael has with panels, but honestly, gouache was never one of my preferred mediums and I defer to his judgement. Finally, individual experiences with a technique is such a complicated issue as so many variables are possible.