Problems during Printing ...

Question and Answer: Preventing Mold

Q: (from Dave Bull) "My apartment is not air-conditioned, and during the rainy season and through the summer when the humidity is very high, I have a problem with the paper becoming moldy during the process of printing.

The advice I received from a few of the older printers here (Tokyo) was to use 'Formalin' to stop the mold. ... Last year though, I saw a story in my newspaper that cited Formalin as being a carcinogen, and so have stopped using it.

How do you guys handle this problem?"

A: (from Dan Wasserman) The following may work if the paper is kept in a sealed container. Rubbing alcohol fumes produce an mold unfriendly environment in closed quarters but vapors off quickly when the paper is left out for any time, but the question is, would it harden the paper size? Clove oil fumes off a rag or sponge would also serve but anything else like boric acid would I'm sure pose an archival problem... I understand printing in the old days was very seasonal. ... I think I would buy an old refrigerator if I were you.

A: (from Bill Mixon) One strategy used in a papermaking class at SMFA last summer, to preserve the buckets of wet pulp over the hot nights for the next day's class, was to pour a little mouthwash (brand probably not too fussy) into it. This seemed to work, up to a point (we had some pulp last _almost_ a week). Certainly it's less toxic than Formalin. I'd imagine that brushing a dilute solution of the stuff over the printing papers, or even mixing it in with the damping water, would do the trick.

A: (from Bill Mixon) Another thought. Rather than using fungicides of questionable safety and side effects, perhaps you could just schedule your summer printing sessions as multiple shorter runs (say two or three of 40 to 60 prints each)? That way each run might fit within the time limit imposed by those little mold spores!

I realize this would probably be a pain on several fronts: extra setup and cleanup time, and extra difficulties of color-matching between runs. But throwing away good paper gone bad is an expensive pain too. One has to find a balance point...

A: (from Matthew Brown) The trick I rely on the most for this scheduling difficulty is the freezer. If I get interrupted, etc. the prints go into a plastic bag into the deep freeze. Have that bag airtight and your moisture content should be the same when they come back out (given several hours to come back to room temp).

A: (from Graham Scholes) Noboru Sawai, my teacher, gave me some chemical, Thymol I believe is the name. It retards the mold forming in paper. You put about 2 crystals in one liter of water. I use distilled water.

A: (from James Mundie) There is a product you might want to consider for your mold problem as an alternative for formalin. Shaklee Corporation out of San Francisco makes a biodegradable concentrated disinfectant/germicide called "Basic-G" that might fit the bill (the label says "psueodomonacidal, staphylocidal, salmonellacidal, fungicidal..."). I use it around the house for various cleaning chores. It's harmful to skin in its concentrated form, but one generally uses only a few drops to a litre of water. Its pH is neutral, so it probably would not have any detrimental effects on the printing process.