MITRA Forum Question Details

I do not have experience with that specific product but have used keytone resinous varnishes in the past. If it is made from keytone N (which it could very well be) this makes a workable varnish with agood degree of saturation. It is not completely non-yellowing (really almost nothing is absolutely non-yellowing) but is is not a bad choice. How old is the product? It is my understanding that keytone N is no longer being made. They may just have a stockpile (I know that they still offer manganese blue in their oil paint line although it has not been made for quite some time).

As to whether one can overcoat a glossy varnish with a matte one, many actually suggest applying a gloss varnish first if one is going to apply a matte varnish later since the gloss creates a more contiguous surface coating. This is probably not necessary with oil paintings. I would also want to make sure that the result would not be too matte for your needs. Perhaps you would be better off mixing matte and gloss together to create satin or other degrees of gloss. As in all things, test first.

Just how successful this will be will depend on a number of factors. If you gloss coating is quite thick and you are brushing on the additional coat, you may cut into it and create areas of mixed gloss and matte creating an uneven surface. Spraying would be preferable if possible. Additionally, a surface made less glossy by the addition of a coating containing matting agents does not look EXACTLY the same as one that is less glossy due to having less varnish on the surface.

So, like so many things, it depends. If you do try to recoat with a varnish with a lower gloss, make sure that you let the lower varnish completely dry for a few days to lessen the chance of picking it up with the subsequent application.

Others may have more direct knowledge of this particular varnish or even a different opinion on the manner.

​Old Holland's literature describes both Matte and Gloss Varnish as "ketone resin dissolved in white spirit" with beeswax listed as the matting agent in the Matte product. They do recommend 1 week's drying time before top-coating (though they don't directly address layering matte over gloss). I don't see any reason why, as Brian suggests, the two couldn't be combined to achieve gradations of surface sheen. 

​I looked that up on their website and see that is the case. My local art supply store still has the OH oi paint containing the true pigment but I doubt that it is a fast mover in my town;)