Patagonia Men’s Keystone Species Cotton T-Shirt. Everything is connected, the Keystone Species Cotton T-Shirt reminds us how many beings draw their sustenance from free flowing and healthy rivers. The tee is made of standard-weight, ringspun 5.4-oz 100% Texas co-op organic cotton jersey and artwork by Lucy Engelman is printed using PVC- and phthalate-free inks. Taped shoulder seams and ribbing at the neck for superior comfort. Coverstitched neck and armholes provide a clean finish. Sturdy side seams keep garment from twisting and shrinking when washed. Fair Trade Certified™ sewing.