This refers to using materials/methods that are of archival quality (acid-free, lignin-free, chemical-free) that will not degrade, discolor, fade or warp the photograph itself. Museum and gallery use archival-quality methods to preserve the collections and work of artists for its lifetime.
This is refers to using materials/methods that do not preserve the photographs. Materials may have chemical properties that will destroy the photograph over time such as economical frames.
A naturally-occurring bonding element that holds wood fibers together. Lignin breaks down over time, becoming yellow and brittle. (Think of an aging newspaper.) Lignin is acidic and contributes to the deterioration of photographs and paper. When it is removed, the aging process slows significantly.
The process of having a photograph print "mounted" onto a substrate or medium to provide rigidity, durability and preservation such as backboard and matting. This keeps the photograph straight, flat and prevents warping from moisture, humidity, etc.
"Matting" a photograph provides protection and preservation from the glass of the frame - it provides separation of the print from the glass. The glass may have chemicals that can migrate onto the photograph causing degradation. Photographs that are framed without any mat or backboard are considered non-archival and may result in permanent damage to the image.
Photographs in general are framed to provide protection from the elements such as moisture, humidity and UV light. Proper "framing" involves a three step process:
Formaldehyde is a flammable, colorless, strong-smelling chemical known to cause cancer that is used in pressed-wood products, such as particleboard, plywood, glues and adhesives. It is found in all low-cost, economical picture frames found at your local retail stores. Overtime, it will degrade and emit an strong odor.
Gallery Canvas Wraps -
Photographs are printed canvas material that are stretched onto a wooden frame and are ready to hang. This is an alternative to Framed prints as it is lighter and doesn't requiring additional steps to preserve the image.