What makes sebum so sticky?

[Contemplation]

Sebum, not semen. Its the stuff that makes hair greasy, yet without it hair would be dull and brittle. Its composed of oils, fatty acids, wax esters, squalene and other things.

But what component of sebum actually makes it sticky and clump to things?
Not all oils are sticky. Would it be possible for a creature to have slick sebum instead of oily sebum?

[Exapno_Mapcase]

It is not the sebum directly that causes clumping, but the production of excess sebum.

While its function is to lubricate and protect, it is possible to have too much. When an overproduction occurs, it can lead to acne and scalp issues. Excess sebum is often caused by a genetic predisposition, a build-up of products, or a condition like seborrhoea. According to DermNet New Zealand, seborrhoea causes a surplus of oil to be produced. It affects both males and females - and has a number of additional side effects, including red and itchy skin.

An overproduction of sebum on the scalp may result in undernourished roots. Board-certified dermatologist Dr. Marder writes on his blog, “because excessive sebum can block hair follicles and spur bacteria and fungi growth, is important not to neglect an oily scalp.” When sebum builds up, it eventually hardens.