How Light Damages Your Books

Exposure to the ultraviolet rays of sunlight and fluorescent light causes the rapid deterioration of paper, leather and fabrics; similar, but less severe deterioration will occur with exposure to visible light, the rays at the red end of the spectrum being less damaging than those at the blue end.

The visible effects of light include: the bleaching or fading of paper; and the yellowing or browning such as rapidly occurs with newsprint. Not immediately visible is the breakdown of fibers into smaller units, causing the paper to disintegrate. Unfortunately, the reactions continue after the source of the problem is removed, although at a slower rate.

Other factors being equal, paper stored in complete darkness will last far longer than that which is subjected to light. However, as totally dark storage is not usually practical, other precautions must be taken. Paper should never be stored in direct sunlight or under unshielded fluorescent tubes. Special ultraviolet-filtering materials, such as UF-3 Plexiglas or Acrylite OP-2, may be used to shield windows or fixtures.