is produced by the sebaceous glands.
Sebaceous glands produce the oily, waxy substance called sebum (Latin, meaning fat or tallow) that is made of fat , wax, and the leftover dead fat-producing cells. In the glands, sebum is produced within specialized cells and is released as these cells burst; sebaceous glands are thus classified as holocrine glands. Sebum has no smell, but its bacterial breakdown can produce a bad smell.