Tyler says it right, as usual.
The oil is from the sebaceous gland. According to The Columbia Encyclopedia, the sebaceous gland secretes an oily substance called sebum. Sebaceous glands are primarily found in association with hair follicles but also occur in hairless areas of the skin. Sebum is a mixture of fat and the debris of dead fat-producing cells. These cells are constantly replaced by new growth at the base of the glands. Generally the sebum is deposited on the hairs inside the follicles and is brought up to the surface of the skin along the hair shaft. In hairless areas, the sebum surfaces through ducts. Sebum lubricates and protects the hair and skin and prevents drying and irritation of membranes. Excessive secretions of sebum may be related to certain forms of baldness.
So, the oil is produced by the glands, and without hair to conceal or otherwise keep it from being noticed you get an "oily" scalp, whether or not it's naturally shiny.
I found by accident that Gold Bond lotion seems to retard my natural shine--I put it on in the morning before I go to the gym after washing my face and scalp and no shine. Another moisturizer that seems to do the same thing is Curel, a odorless concoction that's used in hospitals to preserve skin texture. Finally, Banana Boat Sunscreen also retards shiny. All of these however, don't stop the glands from pumping oil to the surface. That's where Baldwipes, or other similar products are good.
I don't have a problem w/ shine, I like it, but maybe this iwll be of some help to those of us who don't like to "be a light" to the world.
