The term refers to special methods and materials used to frame an item of significant sentimental or monetary value. Various items require different considerations, but here are the basic rules:

• Framing should involve no permanent changes to the item. That means no trimming, folding, pressure sensitive or heat-activated glues or tapes.
• Mounting should be completely reversible at any future time. The item should be easily restorable to its original condition.
• Mats and backings in direct contact with the item should be museum-grade, 100% rag board or lignin-free alpha-cellulose board. “Acid-free” standard wood-pulp matt boards are not museum-grade and would eventually cause damage.
• Glazing (glass or acrylic) should be an ultraviolet light-filtering type, to prevent fading. Common non-glare glazing has no more protective qualities than regular glass. UV filters are invisible coatings on the inside.
• Glazing should not press against the item. Mats or spacers should be provided to hold them apart. The resulting air gap is important to avoid mould.
• Framing should provide protection from normal environmental hazards. Proper framing protects against damages that can be caused by temperature and humidity changes, dirt, insects, and airborne contaminants.

Is it worth the price?

Preservation framing typically costs 25% to 35% more than standard framing. The decision as to whether your item is worth that extra cost is up to you. We recommend it for anything original or irreplaceable, or for artwork likely to increase in value over time. When we speak of value, we refer to both monetary and sentimental values. Here are some things you should know:

• Anything collectible keeps it greatest value if it is in pristine condition. Whatever happens to change its original condition is considered to be damage and reduces its value.
• Standard framing methods and materials almost always change the condition of (damage) the item being framed. Immediate and permanent damage can result from standard mounting methods and materials such as dry mounting — common for non-collectible items, but unacceptable for preservation. Not all changes are immediate; discoloration from acid burn, for example, is slow but cumulative damage. Also, foxing (mildew), fading and other environment-related damages are usually not prevented by standard framing.
• Preservation framing can prevent damage. Damage already incurred can usually be repaired but at a significant cost.