Unprotected prints surfaces are delicate and easily damaged in handling. Print surfaces should never be touched because oils and acids contained in fingerprints will discolor and damage any print over the decades that follow. Also, physical contact with the delicate print surface can cause scuffing and other damage.
Mounting is the first step in framing a print. The print is mounted to a sturdy backer or mounting board to keep it flat and rigid. Matting is the second step. A window mat is placed over the mounting board and print. The edge of the opening in the window mat overlaps the edges of the print, sandwiching it between the window mat and mounting board. The purpose of the window mat is to keep the surface of the print from direct contact with the glass. A second window mat may be applied for what is known as "double matting". In this case, the second mat is cut to allow about 1/4" of the first mat to show immediately around the image. Now comes the glass. Glass with the same outer dimensions as the backer and window mat is placed over everything. This glass, window mat, print, and mounting board sandwich is then put inside a frame and secured there. Simple, isn't it? There are a few variations. for instance, prints are sometimes triple matted to allow more room between the print and glass. This can also give a different decorative appearance.
Prints may be permanently adhered to the mounting board by dry mounting. This process uses a sheet of material that melts at a low temperature. It is cut to size and placed between the print and the mounting board. Heat is applied in a press, fusing the print to its mount. Other adhesives should never be used. Adhesive materials may contain acids, which over decades can discolor and deteriorate the print as well as the mounting and matting materials themselves. In archival work the print is often mounted so it can be easily removed for placement in a different mount and mat in the future. There are a number of these mounting techniques. All of them rely on holding the print only around its edges so it can be removed in the future if needed. Acid-free materials should be used to considerably extend the life of the print. Archival mounting and matting materials are obviously more expensive.
The only difference between normal and archival matting is that the materials used in archival matting are free of acids and other materials that can harm the print. The mat board is more expensive and may not come in all of the colors available in normal mat board.
Prints must be mounted behind glass or Plexiglas. These materials seal the print from harmful airborne pollutants such as dust and ozone. Plexiglas saves weight and will not shatter and damage the print, mat, and frame if an impact occurs. Its surface can scratch more easily, so care must be exercised in cleaning.
There are special types of glass that employ invisible coatings to inhibit damaging ultraviolet light and eliminate reflections. Glass that employs only a coating to inhibit ultraviolet light and can be useful in situations where a print is subject to unusually bright illumination from indirect sunlight or fluorescent sources. Glass that employs both UV and antireflection coatings costs more than $120 for a piece 18"x24") and is nearly invisible, creating an impressive display that looks as if no glass is present. We believe normal glass or Plexiglas is sufficient for most situations, but we make these specialized glass types available to our clients who require custom framing.
We do not recommend or use any glass that uses slightly frosted or etched surface to prevent reflections. Although this type of glass helps to prevent unwanted reflections, it obscures fine detail in the print. When an image printed on matte finished media is mounted behind normal glass or Plexiglas, all surface reflection from the print is eliminated but normal reflections from the glass remain, somewhat masking the matte finish of the media.
The only truly archival framing material is metal, most typically aluminum. Metal frames are available in a variety of styles and finishes. Finishes are either anodized or baked at high temperatures, so they emit no vapors. Wooden frames can contain undesirable acids and can have finishes with unknown archival properties. The potential for print damage is minimal, but over decades it is possible. The matting material and mounting board, which are in direct contact with the frame, can be more rapidly affected.
Archival Display of Framed Prints
Light fades all pigments and dyes, regardless of whether they color your house, car, couch, carpeting, or fine art prints. Normal tungsten lamps cause the least amount of damage and sunlight causes the most. Direct sunlight is so powerful that over time it disintegrates cloth, paper, and plastic, and fades any coloring agent. The only hard and fast rule about print display is that no valuable piece of art should ever be displayed where it is exposed to the direct rays of the sun.
Cleaning Framed Archival Prints
Clean your framed print carefully, using a soft, lint-free, cloth. The cloth can be dampened with water, or if necessary, a glass cleaner. Do not spray the cleaner on the glass directly. It can run down between the frame and glass, and then soak into the mat board. Ammonia and other destructive gasses are then trapped under the glass with the print. Over time, these can attack and discolor the print.