"pelt" sighting: Seals & Sealing Network

Both harp and ringed seals are "hair seals" which depend on their blubber as their main defence against the cold. Their pelts therefore have no underfur, and are comprised entirely of short, shiny guard hairs.
The result is what is called "flat" fur, of which hair seal fur is the longest wearing of all, much more durable than calf or antelope, for example.

Flat fur is not as warm as a "true" fur like mink, which has underfur. However, its high oil content helps repels rain, and its structure resists wind, while its porosity allows it to breathe.

Read more here.