Silk

Silk is a continuous protein filament reeled from the cocoon of the Bombyx mori silkworm, made of fibroin (the core fiber, roughly 75 to 80 percent) wrapped in sericin, a gummy coating. Most sericin is stripped off in a hot-water or enzyme step called degumming, which is where finishing chemicals and dyes also enter the picture.

Properly degummed silk is one of the most skin-friendly fibers you can wear. Its smooth filament structure and ability to manage moisture and temperature mean it breathes, wicks, and regulates heat against your skin, which lowers irritation and supports your skin barrier. The catch is residue: low-quality silk that keeps too much sericin can be read by your immune system as foreign and trigger histamine release and contact allergy, and the dyes and finishing agents layered on during manufacturing are a more common cause of allergic contact dermatitis than the fiber itself. If silk irritates you, suspect the finish, not the protein.

Choose fully degummed silk and look for OEKO-TEX STANDARD 100 certification, which tests for 350-plus harmful substances including dye and finishing residues. Higher-grade silk with thorough degumming is the most hypoallergenic option.

Conventional sericulture is land-light but energy- and water-intensive, since cocoons are typically boiled to reel the filament.