 For venous stasis ulcers, the paste-impregnated wrap is covered by an elastic layer, generally an elastic wrap ("ACE" bandage) or self-adherent elastic bandage such as Coban; this is referred to as a 2-layer compression bandage.An alternative treatment is a 4-layer, graduated compression wrap (Pro-Fore is an example).Evidence indicates that both are equally effective in healing venous stasis ulcers — a slow process in the best of circumstances, often taking 2–6 months.