Like matboard, these folders must be made of lignin-free, buffered stock that is rigid enough to provide adequate support. To protect the edges of the artwork, folders should be somewhat larger than their contents. These files should be made of metal rather than wood since wood gives off acidic gases. If you purchase storage drawer units, anodized aluminum or powder-coated steel are recommended. It can also darken or embrittle paper.
Light damage is cumulative and irreversible.
Because all light will cause damage, conservators recommend that no work on paper be permanently displayed. The best display conditions are those with low light levels and no daylight. Block windows with shades, blinds, or curtains. UV is found in all daylight, most abundantly in sunlight, and in the emissions of certain artificial lights, such as most fluorescent and metal halogen lamps. These bulbs give off heat, however, and should not be placed near the artwork.