What's under the yellowed crust of varnish on renaissance paintings

Originally published at: https://boingboing.net/2017/11/07/whats-under-the-yellowed-cru.html


No photoshop.

I am disappoint.

When the Rijksmuseum in Amsterdam removed the polluted varnish from the Rembrandt piece commonly known as “The Night Watch”, they discovered that it wasn’t a night scene at all.


That is pretty impressive. :slight_smile:

Must take quite a bit of research and experimentation before you can come up with something that clears the varnish away without harming the paint beneath.

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My question is, what do they experiment on? Is there a trove of crap Renaissance paintings that nobody wants, that happen to use the same paints as the “masterpieces”?


I once met someone who worked on the chemistry of art conservation; she had a collection of paint samples from old paintings, most about the size of a pinhead.

There are also non-destructive methods, like Raman microscopy, and X-ray fluorescence.


Mould later clarified that the “woman in red” is 36 years-old and was painted in 1618…

Time travel!

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I had the luck to speak to a conservator I met in the street. He told me one of the worst elements to work against is impatient painters, who try experiments like mixing varnish in with the paint, or not waiting long enough for the paint to cure before varnishing (with the real deal Damar, not touch-up varnish). He said it’s even risky to play around with mediums and “extenders”; that pure, unadulterated paint is the best, and wait a few months before varnishing. Then there’s less paint loss upon restoration.


I’ve been told they sometimes test on the over panted areas that end up wrapped around the canvas stretcher under the frame. Not visible not part of the painting. Seems to be where they pull samples for most potentially damaging things.


Either that, or the last thing Rembrandt did to it was apply a coat of nightenizing varnish.

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As an Art Conservator who holds a masters degree from an accredited US Program, with over 10 years of professional experience, and who has worked at major institutions while abiding by a Code of Ethics to do no harm, This is in NO WAY representative of conservation. To treat a painting this aggressively with agitation, and allow the public to think its that easy is irresponsible. Art Conservation involves a lot of time, testing, chemistry, and discretion. Please do not glorify this treatment.

Yep. That and the skills of extremely patient restorers who progressively remove incredibly tiny flecks of paint until – by observation – determine that they’ve removed what shouldn’t be there and successfully reveal the artist’s true rendering; many restorations require that type of technique.

Last month I topcoated a found piece of plywood graffiti. I used Golden’s UV-shielding archival varnish (mineral spirit-based) and I recall reading something similar in their instructions.

Tom Keating in ‘The Fakes Progress’ remembers working with the team restoring the Mantegnas at Hampton Court (roughly the same age). This was done with Nitromors, a razor blade, and a sponge. You spread on the Nitromors, one, two, three, scrape with the razor, wash with the sponge. If you kept it quick, you could remove the top layer of the varnish that had all the yellowing, even if the stuff under it was chemically the same, without scrubbing. But, get it wrong and the lot comes off.

It is hard to do the same on the Mona Lisa because of Leonardo’s ‘sfumato’ finish, which involved many layers of deliberately tinted varnish. It would be hard to know where the pollution stopped, and the art began.


So you don’t recommend Ajax and a Brill-O pad?

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I know nothing about restoration but having the loosened goo run over a clean area makes me cringe…

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Art by the pound!

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Now, to a more difficult task:

I saw Mr. Bean try the same thing on Whistler’s Mother.

‘Paint me out front’ she said, contemplating how drape would change in 399 years, ‘how about that?’ It changed the 400th year.