They are easy to apply - just peel and stick. They are also used on matted pieces when the artwork is very heavy, such as watercolors. This is the material used behind the backing board or artwork. The filler board acts as a barrier against acid migration and dust, fills space, and adds rigidity to the finished frame package. We do not recommend standard corrugated boards because of their acidity.
Dust covers keep dust and insects out and slow the rate of temperature and humidity changes.
The traditional method is to cover the back of the frame with kraft paper. We recommend using dust cover tapes. They are available in regular and acid-free versions. Metropolitan Picture Framing 6959 Washington Ave.