Posted by Andrew (75.3.67.238) on July 05, 2011 at 00:53:05:
In Reply to: Re: Toyokuni I - bust portrait in pr posted by geo. on July 04, 2011 at 23:43:38:
Exactly what will happen depends on what kind of inks were used, which in turn depends on the period. Shin-hanga is a lot different situation from Meiji, which is different from mid-Edo, which is different from late 18th-century and early-19th Japanese prints.
And also which colors were used.
Most of the Meiji red, purple, and yellow inks are aniline dyes which are very water-soluble, that's why so many Meiji prints are wrecked from having been stored in contact with one another.
If you have some prints in poor condition, your goal is to bleach out stains regardless of consequences, and you are aware that the bleach itself is damaging the print in another way, well, it's your artwork and your aesthetic prerogative.
While you were handling the 25% H2O2, did you ever get a few drops of it on your fingers? See how the skin turns completely white, then peels off later? Oxidative bleaching is a dire choice, it's not harmless.
Some colors are attacked by the bleach more than others because the molecular structure of the dye (usually related to the length of the double-bond chains) varies as well as how easily it can be oxidized. And some are washed out more than others depending on water-solublity and fastness of the binding to the paper.
It would be a bad idea in the case of this particular print, and I would really not recommend it in general, either. That's all that I was saying. It's not morally scandalous to damage prints which are already badly damaged, so don't take the critique personally.
Peace,
Andrew