This test method is applicable for determining the relative compression and recovery of fibrous insulation padding materials. 1.1 Purpose The purpose of this test method is to establish a means of measuring the ability of fibrous insulation materials to resist compression and recover after being compressed, dry or wet. It should be noted that there are several test methods. These methods have been found necessary for different loading applications, variation in surface density of the padding materials and the requirements of different vehicle manufacturers. The results of these test methods cannot be correlated directly to each other. The material specification should indicate which test is necessary for a particular application.