Light micrograph of human thick skin stained with the Cajal-Gallego method showing, from top: the epidermis with a thick stratum corneum or horny layer, the dermis, with abundant collagen fibres stained blue, and the hypodermis or subcutaneous tissue, with adipose (fat) tissue lobules separated by thick connective tissue sheets rich in collagen fibres. The scale bar corresponds to 2 mm.