I just received a framed poster that has mold on the surface. Not heavy, but visible. The poster looks cheap and was vintage 1970 or so. Always, the customer desires a quick fix. Any suggestions on how to get the mold off?
Loose mold can be brushed off with a soft brush, or wiped with something soft like washed cotton flanelette.
It it is a bit more stuck on, you can use grated art gum or white vinyl eraser - grate it on the fine part of a cheese grater - and gently roll it across the surface with fingertips. Stop it if looks like you're picking up any pigment.
If it's actual stains you'll likely have to send them to a paper conservator who may, or may not, be able to remove them.
understand the brushing off(do that OUTSIDE and do it downwind & think about spritzing yourself with lysol, etc--you dont need to help import any more spores than is normally unavoidable! BUT all those vile little spoors are already present in the paper..given time it'll just want to grow back! Make sure customer is aware it'll happen (I even go as far as writting that on the contracts so there "should" be NO confusion down the road when that crap shows up again)
This is something that Hugh would discourage, but, with the customers permission after informing him/her of the risks, I have had good luck by treating mildew stains with a 1 : 20 dilute solution of Clorox and water.
I use a cotton square dipped in the solution, squeeze out the mixture so that the pad is just barely damp, then gently rub it over the mildew. This should kill the spores. There may be some residual staining because of the mildew, but the Clorox will prevent it from getting any worse. And, sometimes, if you get lucky, the stain goes away completely.
Once this is done, go over the area with just a <u>damp</u> pad with water to get rid of the residual bleach.
Clearly, with any really valuable pieces, you would want have this done by a conservator, but for those cheapo prints that the customer doesn’t want to spend any money on, this has worked pretty well for me.
I may be wrong on this. Many years have passed since I heard that Sodium Thisulfate will neutralize chlorine bleach. Sodium Thiosulfate was used as a fixer for black and white photographs. Aparently it has been replaced by another thiosulfate. If anyone feels the need to follow this, you might talk to a chemist first.
Chorox is a very strong bleach and, unless it is neutralized, can still be active.
The paper, after the bleach solution, should be placed under blotters and weights to minimize distortion.
I also heard that active mold can be killed with direct exposure to sunlight . I don't know if the spores are affected though.
When I hear "quick fix" the alarms start going off in my head " DANGER DANGER DANGER". Even if you inform the customer of all possible outcomes you can still leave yourself responsible for any damage to the art. In addition if the customer is not happy with the results you run the risk of creating a bad publicity machine walking out your door. Sure brush off that mold off their poster and spread it all over your shop. You can play the guessing game and try what you think will fix it but why risk it. I think it is ill advised to attempt conservation unless you are trained to do it properply with a high percentage of a successful result. That's what professional conservators are for.
I would be skeptical using advice preceeded by:
I think I remember
Someone once told me
I once tried