The authors worked out a simple method, which enables an orientative evaluation of different skin substitutes as to their effectiveness in preventing gross evaporative water loss from decorticated dermis. The method is based on the loss of weight of decorticated dermis samples (covered by different materials) incubated in a thermostat for 1, 2, 3 and 4 hours at 37 degrees C. Following skin substitutes were tested: Lyofoam; Epigard; collagen foil; freeze dried amniotic membrane; freeze dried porcine xenografts; deep frozen porcine xenografts; and fresh porcine xenografts. Controls lost during 4 hours incubation at 37 degrees C 61.34% of the original weight (similarly as samples covered by synthetic skin substitutes or amniotic membrane). Samples covered by freeze dried xenografts lost only 33.07%, samples covered by deep frozen xenografts 13.20% and by fresh xenografts, 6.06%.