Light microscopy of thick skin. The superficial layer of skin is the epidermis. In thick skin the surface layer has distinctive folds made of keratin acting as a barrier for protection of the deeper tissues. Beneath this is the epithelial cell layer of the epidermis which is renewable. The keratin which is non-cellular, is the end product of development of the epithelial cells. The folds or ridges of the epidermis are responsible for fingerprint patterns. Ducts from sweat glands pass through the keratin layer. The dermis (lower half) is deep to the epidermis and is formed mostly of connective tissues. Magnification x60 when narrow width printed at 10 cm.