The skin has 2 basic layers, dermis and epidermis.
The epidermis is the external structure and is made of layers of dead or dying cells separated by layers of lipids. The lipids protect and retain the moisture held in the deeper layer of the skin. These lipids account for 14% of the total weight of the skin.
The dermis is a mixture of protein, fibres, collagen and elastin. The moisture is retained in the collagen. It contributes to the plumpness, smoothness, elasticity and youthfulness of the skin. This will dehydrate quickly if the lipid barrier is poor or damaged, resulting in sagging skin forming wrinkles etc.
The body produces its own protective oil – sebum a mixture of fatty acids and glycerides. It is produced by sebaceous glands which are are most active after puberty. Their activity decreases as the body get older.
Cold pressed botanical oils balance the production of sebum at the different ages and stages of life. They are used because of their low incidence of irritation, sensitivity and because many of them are non pore clogging.