A remarkable Jacobean re-emergence after 200 years of yellowing varnish Courtesy Philip Mould
PAINT RESTORATION OF MESMERIZING
I saw this on Twitter. He’s using acetone, but a cellulose ether has been added to make it into a gel (probably Klucel—this entire gel mixture is sometimes just called Klucel by restorers, but Klucel is specifically the stuff that makes the gel).
Normally, acetone is too volatile for restoration, but when it’s a gel, it becomes very stable and a) stays on top of the porous surface of the painting, and b) won’t evaporate. So it can eat up the varnish.
It looks scary, but acetone has no effect on oils, and jelly acetone is even less interactive with the surface of the paint or canvas.