DownProof wash-in treatment reduces the water-absorbency of down and adds water-repellency to the fabric's outer shell. It makes down less susceptible to humidity helps it dry faster and increases the effectiveness of the insulation in damp conditions by helping the down maintain maximum loft. DownProof may reduce breathability of coated or laminated breathable waterproof fabrics. Sleeping bags should be treated in large capacity commercial front loading machines. DO NOT USE A TOP LOADING MACHINE.