Performance Appearance Rating and Carpet Assurance Program, respectively. These are measurements of the carpet's wearability. A PAR of 3.5 to 5 and a CAP of 8 to 10 is good for moderate to high traffic areas. Carpets are then rated according to how well they stood up to the wear. Most backings are made of plastic.
Most carpets have a primary and a secondary backing.
The tufts of fiber are sewn through the first backing with needles. Latex glue is placed between the backings in order to hold the tufts into place. The latex glue that is used is very important. If the glue is cheap, and therefore begins to break down in time, the fibers will begin to fall out and the carpet may begin to show ripples. As a general rule of thumb, higher priced carpets use a better quality latex.