What are the different types of silk?

Silk is a natural protein fiber produced by silkworms, and there are several distinct types, each with different properties and price points. Mulberry silk is the most common and highly regarded, accounting for roughly 90% of global silk production. It comes from Bombyx mori silkworms fed exclusively on mulberry leaves, producing the longest, most uniform fibers with a luminous sheen. Tussah (or wild) silk comes from wild silkworms that eat various leaves, resulting in shorter fibers with a slightly coarser texture and a natural golden-tan color.

Eri silk (also called peace silk or ahimsa silk) is harvested after the silkworm has emerged from its cocoon naturally, making it a cruelty-free option. The fibers are shorter and less lustrous than mulberry silk, with a cotton-like warmth. Muga silk, produced exclusively in Assam, India, is known for its natural golden color and extraordinary durability — it actually strengthens with washing. Spider silk, while not commercially available for textiles, is being studied for its remarkable strength-to-weight ratio.

For sleep products, mulberry silk is the standard to look for. Its long, smooth fibers create the least friction against skin and hair, and it contains sericin, a protein with natural moisture-retention properties. At ONDU, Promeed uses exclusively 6A-grade mulberry silk — the highest quality classification — for pillowcases, sheets, and sleep accessories.