Nyco 6.6 Ripstop
NYCO fabric is a nylon 6.6 and cotton blend. The key benefit to adding nylon to cotton, is strength.
Where cotton can be a relatively weak and wear prone garment, nylon tends not to be. On the flip side, a 100% nylon garment is often not comfortable, and not desirable looking.
A NYCO blend gives you the best of both worlds: look and feel of cotton, durability and strength of nylon.