The Fabric Files glossary
Staple length
The length of individual fibers; longer staples spin into smoother, stronger, less-pilling yarns (Pima cotton, long-fiber merino).
GSM
Grams per square meter - fabric weight. 180-220 GSM for substantial tees, 300+ for hoodies.
Momme
Silk weight unit (4.34 g/m2 per momme); 19-25mm is the durable range for garments and pillowcases.
Two-ply
Yarn made by twisting two strands together; stronger and smoother than single-ply at the same weight, key in cashmere and shirting.
Mercerized cotton
Cotton treated with caustic soda for luster, strength, and dye uptake; common in better tees and polos.
Elastane
Synthetic stretch fiber (aka spandex/Lycra); 2-5% adds comfort, above 5% in non-activewear signals shorter garment life.