In order for a frame to be archival, all of it's component parts must be made of archival quality
materials. At Absolute, we frame for museums and galleries where conservation is the highest
priority. Archival frames that we build for collectors are to the same standard that is demsnded
by such as the Getty and LACMA. Following is a brief discussion of some of glazing materials with
references and links to other websites with more information.
Glazing serves a dual purpose: it provides a protective barrier between the artwork and the environment and it often is an important conservation element. There are many glazing choices from plain window glass up to an awesome product referred to as Optium (a product and trademark of the Tru-Vue Company Glazing products fall into two broad categories: (1) glass; (2) acrylic. There are several quality levels within each of these categories.
With advances and improvements in acrylic products, the use of glass in picture frames has declined
substantially in recent years. Particularly in areas where the earth moves periodically and shakes
frames off of the wall. Shattered glass can do serious damage to framed artwork and may be
be a personnel hazard as well.
On smaller pieces there is less risk and if the artwork is of no or little value such as a poster in a temporary display, clear glass is the least expensive option. At the other extreme, when the art is of value or is particularly sensitive to uv rays, then museum glass is used.
Clear glass filters about 45% of uv rays and reflects less than 8%. A uv filtering glass blocks 99% of the uv and also reflects about 8%. Museum glass blocks 99% of the ux but refelects less than 1% making it almost invisible.
The technical performance of acrylic products is essentially the same. There are the same classifications as glass (i.e., clear, uv filtering. museum grade). Acrylics have an advantage in that they are much lighter than glass and are less likely to shatter on impact. It may crack or break but will likely be less damaging to art and personnel.
Interested in learning more? Following are links to several websites with greater detail.