Foam and padding are usually applied over stockinette. Foams help evenly distribute the compression from the short stretch bandages that will be applies next. Foam can also be built-up over areas that required more drainage.
The same is true of padding. Pads are applied on top of problem areas, like fibrotic or hardened tissue, and secured with gauze. Pads gently stimulate the tissue, encouraging the release of interstitial fluids.