MITRA Forum Question Details

I do not know the specific product you are referring to but the acrylic polymer varnishes that I have knowledge and experience with should not be applied to oil paint. They require a rather alkaline solution for removal (usually made so by the use of ammonia, which is volatile and will eventually evaporate from the varnish as/after drying). Even if the oil paint is not harmed by the application of an alkaline varnish, it would very likely be damaged trying to remove that coating. Oil paint is saponified at higher pHs. In essence, this is converting the fatty acids in the oils into water soluble soaps.

I would be very suspicious of such a product unless it is explicitly/conclusively shown that they were able to make and remove the dried film with a solution somewhere near neutral or even very slightly acidic.

​This one's news to me, too. I'm aware of some varnishes sold for application over finished water-miscible oil paintings, but the varnishes themselves list isopropyl alcohol on the SDS, so I don't think those would meet the standard of "water-based". I can imagine it's possible a destructive interaction could occur between a water-based top coat and some types of painting supports, which could swell or sag from moisture.

​There is no harm in listing the brand and name of the product. I would be interested in how they market the varnish and any possible technical info that they provide. If little is offered, I would like to request some form the manufacturer.

Unfortunately, we do not have a contact at Maimeri. There is no indication of reversibility other than saying that it is “non-yellowing.” I worry about that. I also worry that the safety sheet is a dead or unreachable link, although since I have had to deal with the complexities of web serves since starting this and a technical art history site, I assume that this is an IT issue.

Frankly, unless I read something monumentally new about how they achieve this water-based varnish, I would avoid using it on any oil containing coating.

I will reach out to Maimeri to see if they can provide any additional information.

​I think this is the SDS: https://cdn.dick-blick.com/msds/DBH_SDS_015651294.pdf

One reputable retailer lists this as "non-removable", BTW.

Also Reading over the MSDS, which Matthew was able to find, we see that the pH of the varnish is 9.1, which is too alkaline to be safely applied to an oil painting, especially one that was paintied recently.

What we have is the MSDS and not the SDS. It will be interesting to see what they would be required to include on the newer SDS sheets.