Identifying Mold on Paper
The first step in restoration of paper items with mold is to determine that there truly is mold. Mold on paper rarely looks like mold that appears on other surfaces. By the time it gets to the thick, bluish-green, fuzzy state that we all recognize as mold, it has usually destroyed paper items.
Rather, mold on paper items more often appears as mildew, which is recognizable for its black, white or green spots, or as a thin film of greenish, grayish or even white growth on the surface of the item. Sometimes, as in the case of books or other bound paper materials, mold won't even be recognizable to the naked eye; growing within the binding, mold will only be noticeable by its musty scent.
Restoration of Mold Damage on Paper
Whether you have one item with mold or several with mold, action must be taken immediately to stop the mold from growing and restore the item. Remember that when handling items that have mold, it is wise to wear gloves and a ventilation mask.
If the item is damp, air dry it, in sunlight if possible, as UV rays destroy mold spores. If it is not possible to air dry the item outdoors, air dry it in a room that is dry and ventilated by fans.
For books, air dry by setting the book up on its spine, then fanning the pages. This will also work for magazines or other bound materials, although care must be taken to support the item in order to keep it upright. For maps or other flat paper items, sandwich the item between two pieces of fiberglass or plastic window screening material, and support the screens so that air can circulate both on the top and bottom of the item. Do not use metal screening, as it can leave rust stains on damp or wet items.
After paper items are dry, remove loose mold spores by wiping the items down with a dusting cloth that has an electrostatic charge.
When the loose mold spores have been removed, there may be stains left on the paper. For fragile or antique items, these stains are best left alone.
Ethyl alcohol is the recommended treatment for mildew stains on paper. For hardcover books, it is possible to wipe the covers, head and tail with a cloth barely dampened with ethyl alcohol.
Ethyl alcohol can also be applied, using a cotton swab, to individual stains on other paper items, taking care not to apply the alcohol to the typeface or other printed areas, and also taking care not to soak the paper. Never use bleach or any other harsh chemical on stains on paper; harsh chemicals can eat through paper or weaken them, causing degradation over time.