Sebaceous gland Sebaceous gland Sebaceous glands are microscopic exocrine glands in the skin that secrete an oily or waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals. In humans, they occur in the greatest number on the face and scalp, but also on all parts of the skin except the palms of the hands and soles of the feet. The type of secretion of the sebaceous glands is referred to as holocrine. In the eyelids, meibomian glands, also called tarsal glands, are a type of sebaceous gland that secrete a special type of sebum into tears. Fordyce
Seam sealant a flexible waterproof "seal" by drying (dehydrating) in the case of water borne compositions, or thermoset irreversibly to a flexible adherent seam seal by going through an oven bake in the case of plasticized polyvinylchloride compositions. Most interior seam seals are not visible after the vehicle is finished, because they are covered by carpeting, interior roof headliner, or decorative trim panels. Exterior seam seals are always painted over and are referred to as "coach joint seals." The flat-stream application with many special solutions (special nozzles) was increasingly used as the most flexible procedure. Seam sealant Seam sealants are chemical coating