MITRA Forum Question Details

It is certainly true that in historical works, oil and egg tempera over gold leaf has not fared as well as other parts of the same painting. The gilded surface provides little or no physical tooth and no absorption, two characteristics required for proper adhesion of those mediums. Really, neither oil, nor egg tempera are great adhesives on their own, certainly not in the absence of the above.

Acrylic dispersion media, on the other hand are bound in a far netter adhesive on its own. Glazes composed of those in the proper (not underbound) should fare far better. Perhaps oil over an acrylic dispersion glaze would work but it would seem to be far too slick and non-absorbent. Giving the acrylic dispersion layer some tooth would alleviate this, but it would also diminish the glaze effect you appear to be wanting.

One corollary from the history of painting technique is the preparation of copper panels intended as oil paint substrates. We do know that, at least sometimes, the panel received a coating of garlic juice which seemed to create a better bond between the panel and the superimposed oil ground or oil paint. The copper panels were also usually roughed up before priming to promote better adhesion so the garlic juice was probably not effective enough on it own.

Perhaps others could comment here.

We have found that GAC 200 adheres to imitation gold leaf fairly well and doesn't tarnish the surface like some other acrylic mediums. But it does change the color a little. You could test GAC 200 onto your gold leaf, then try some acrylic glazes over that. You would only need a touch of acrylic color and you could use the same GAC 200 medium as the glaze. GAC 200 needs to be applied in 70F or warmer to form a proper film. There may be other products that are applicable as well, but would require testing.

You could also apply oil glazes over top, but we have found some recent issues with oils over acrylics. You can learn more by reading this article: https://justpaint.org/revising-our-recommendations-for-using-oils-over-acrylics/

Oil applications with high oil content should not cause any issues relative to this phenomenon, but its good to be aware of.

Greg from GOLDEN​