Momme (pronounced "mommy" and abbreviated "mm") expresses the weight in pounds of a piece of material of size 45 inches by 100 yards. So, for example, a 50 yd. bolt of our 5mm 45" Habotai Silk fabric (#HS545) would weigh 2.5 lbs. (plus the weight of the cardboard tube it is wrapped around, of course).
The higher the momme, the heavier and stronger the fabric. Anything above 28 momme is considered heavy-weight and generally used for curtains or heavier outer-garments. Silk under 20 momme is considered lightweight, and generally used for summer weight scarves, linings and light blouses with a chiffon feel. Medium-weight silk (20 to 28 momme) is excellent for warmer silk scarves, furnishings, wedding dresses and the ultimate luxury of silk sheets.