From J. Crew website: We've revamped the super-versatile Secret Wash shirt with premium 100 percent cotton 100s two-ply yarns, plus an improved fit. "100s" refers to a finer yarn size, and "two-ply" means two yarns are twisted together to make a single thread. The result is smoother, stronger fabric. We also use our (proprietary) multistep wash process to achieve a soft, broken-in feel from day one. It's effortlessly casual right out of the dryer and easily polished with a quick iron. Long story short: The customer favorite since 2005 is now better than ever. By buying cotton products from J.Crew, you're supporting our investment in Better Cotton's mission to help cotton communities survive and thrive while protecting and restoring the environment. This product is sourced through a system of mass balance and therefore may not contain Better Cotton.