Ash Grey is 99% cotton, 1% polyester
Antique (Cherry Red, Jade Dome, Irish Green, Sapphire, Orange) and Sport Grey are 90% cotton, 10% polyester
All heather colors as well as Sunset, Safety Pink, Russet, Neon (Green, Blue), Midnight, Lilac, Blackberry, Tweed, Safety Green, S. Orange are 50% cotton, 50% polyester
The color "Natural" is made with unprocessed, unbleached cotton, which results in small black flecks and plant fibers throughout the fabric.
When washing embroidered clothing it is suggested to wash the item inside out. This will protect the embroidery and increase its longevity.