1. Separate glass from the art surface
This is important because moisture will condense where there is no air gap, inviting mildew and mold.
2. Provide a visual background
For this purpose, the wider the mat, the better. If the mat overpowers the art, then the mat color is wrong. Mat width affects the visual importance of the finished piece.
3. Coordinate colors
You can emphasize certain colors in the art and help it fit into the chosen surroundings.
4. Color choice
Top mat should be neutral in color, and of less color intensity than the art. If the top mat dominates, it will distract from the art. Additional mats beneath the top mat can be used to provide accents for color coordination with surroundings or to emphasize certain colors in the art.
Narrow mats are usually more distracting than enhancements. Wide mats create focus toward the art. Standard sizes for ready made and open frames usually correspond to standard photograph sizes. The following are suggested ready made frame sizes, with mats, for various art image (mat opening) sizes.
1. Clear picture framing glass is most common and least expensive for general purposes.
Often called "regular" glass, but should not be confused with lower-quality window
2. Non-glare glass is about twice the price of clear glass. Its etched surface blurs the image when viewed from side angles, especially when glass is properly separated from the art surface; more separation, more blur.
3. Ultraviolet-filtering glass is available clear or non-glare, and is recommended for all preservation projects. It is coated inside to filter out more than 99% of harmful UV light, which causes fading. UV rays are in all types of light, but very strong in sunlight and fluorescent light.
1. Sawtooth hangers are OK for small frames, smaller than 8" x 10".
2. Generally, wire is best for frames up to a weight of 30 lbs. Stainless steel or coated wires are stronger, will not rust or corrode, and will avoid marks on walls. Make sure ends are securely fastened to screw-eyes, and that they are securely fastened to the frame. Use proper size picture frame hangers, not just a nail in the wall.
3. For frames over 30 lbs., use separate hangers on each side of the frame back, and no wire. If a wire is used on a heavy frame, the sides pull toward the center, and corner joints are strained; also, top and bottom rails of the frame tend to bow