The term “foxing” refers to the discolorations and spotting that arise from age on antique and vintage paper. The name derives from the reddish hue of these stains which evoke thoughts of a fox and could perhaps also refer to the rust-color of Ferric Acid. The phenomenon is thought to be caused by mold or the discoloration of elements within the paper itself. Foxed paper is not permanently damaged. The staining does not affect the integrity of the paper itself. A capable conservator can undo the stains of foxing with relative ease. Foxing does affect the value of antique papers. However, with the assistance of a paper conservator, the value will be restored.