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.
The most important use of seal pelts is for utilitarian clothing used by the sealers and their families, such as vests, jackets, skirts, trousers and headgear. They are also used for fashion items, and for accessories such as purses and bags. They take dye very well, though this treatment is normally reserved for lower grade pelts.
Other important uses include tents, for the skins of kayaks, and for making rope.
Traditional Inuit seal goods take time and work to produce. The tough hides are first softened with products such as baking powder and dish soap. They are then scraped and broken by hours of kneading. They may then be left for a year or more to cure.
Other species of seal, such as the Cape fur seal, do have underfur. When used for clothing, the guard hairs are plucked and the underfur sheared to produce a soft, velvety "duvet", much like preparing sheared beaver.