Impact resistance measures the a coating material’s resistance to sudden mechanical impact without undergoing any physical changes - meaning that it takes the form of its substrate without cracking or fracturing itself. This is a common indicator to see if a surface has sufficiently cured, with its coating crosslinking strength enough to withstand mechanical deformation. ASTM D2794 has a flat, coated panel placed under a weighted spherical ball assembly, with the weighted ball subsequently raised to a certain height and dropped onto the coated panel. The impact causes a dimple indentation on the surface which is then examined for cracks and degree of cracking. This impact test is often done on both sides of the panel for a complete picture of impact resistance.