Since the best preservation of a print is due to its close knowledge (as the more you know about it, the more you wish to safeguard it), the most frequent damages are: an incorrect exposure to light; an unsuitable placement; an incautious handling of the print. The easiest way to avoid these damages is to pay attention to framing, to the place where you set it or where you preserve it, if it’s not exhibited.
The cardboard used for the passe-partout must be neither acid nor basic (neutral PH), and it must be subjected to a treatment against fungi to neutralize the microorganisms that may be found in the cardboard. During the framing never use gummy adhesive or water-insoluble glues (for example vinyl glues), which are often oxidizing, that is, in the course of time, they turn yellow or get dark.
You don’t have to choose walls which receive direct light, particularly the natural one. In fact solar light contains ultraviolet rays which can cause the paper chemical reactions. Avoid walls where chimney flues pass or walls over radiators, because the warmth they release carry dust and grease upwards.
You must lay them in portfolios, in a dry place without sudden changes in temperature. It’s better to separate the engravings with tissue papers to protect them from dust and continuous friction with the other prints.