The Durometer Measurement Standard
Durometer is the international standard for measuring the hardness of rubber, foam rubber, plastic, and most nonmetallic materials. Foam rubbers are usually measured on the Shore OO scale, and solid rubbers on the Shore A scale. In some cases, an object may fall within more than one scale. For example, a typical shoe heel is 95 Shore OO, 70 Shore A, and 22 Shore D durometer.