The effects on superficial wounds in domestic pigs of (1) two different occlusive dressings, (2) non-occlusive wet to dry gauze dressings, and (3) air exposure were compared. Collagen synthesis and re-epithelialization were increased in the wounds treated with occlusive dressings. Re-epithelialization was increased beneath both the oxygen-impermeable and the oxygen-permeable dressing. When they were removed the wet to dry gauze dressing and one of the occlusive dressings often damaged the new epidermis.