This is the Filson Mackinaw Wool Jacket Liner, a warm virgin-wool layer designed to zip or wear under a shell, coat, or field jacket when the temperature drops, then come out when it warms. Made from the same heavyweight Mackinaw wool as Filson’s jackets, it delivers real insulation without synthetic fill.
It extends the season of an outer layer, adds core warmth on cold mornings, and works on its own indoors or as a standalone midlayer. Wool insulates even when damp, which makes it dependable in wet cold.
Filson has outfitted workers and outdoorsmen from Seattle since 1897, and its Mackinaw wool garments are cut and sewn in the USA from heavyweight virgin wool.
