Foxing

Biography

Foxing is a process of long-term deterioration of materials that causes the appearance of stains and browning, particularly on old paper. This phenomenon is found on archival documents, books, and postage stamps. The term comes both from the brown-reddish color of the stains and from the ferric oxide that causes rust stains. The term often used in library science to designate this phenomenon on old works is foxing spot. Foxing is rarely present in incunabula. The decline in quality of the fibers composing the paper may be the cause.