PrimaLoft® is a brand of patented synthetic microfiber thermal insulation material that was developed for the United States Army in the 1980s.

PrimaLoft synthetic insulation is used in winter clothing, outerwear, gloves, sleeping bags, and footwear.

[3] In 2010, PrimaLoft was the first maker of branded insulation to be recognized for compliance with the bluesign criteria for environmental effect.

[7] In 1983 the U.S. Army Research Laboratory in Natick, MA approached PrimaLoft's former parent company Albany International Corp., a global advanced textile and material processing company,[8] to develop a water resistant synthetic alternative to goose down for use in military sleeping bags and clothing systems in variable environmental conditions.

The U.S. Army was primarily interested in a synthetic insulation that would be comparable to goose down in weight, compressibility, and warmth, but also retain heat while in the presence of moisture.

A 1990 New York Times article titled "Outdoor Wear: Sorting Out the Choices" featured statements by Edward Howell, then L.L.

[citation needed] In cold and dry areas, down provides warmth and comfort but it becomes a liability when it gets wet.

[14] The warmth of clothing is influenced by the type of PrimaLoft used and its thickness, with thicker insulation trapping more heat.