Mens/Unisex shirts are printed on American Apparel 2001 or Bella+Canvas 3001  and Ladies shirts are printed on Bella "Favorite Tee" 6004, all of Ring-Spun Super Soft Jersey Knit. 3XL and 4XL may be substituted with Gildan or Hanes in closest color match. Not sure what size you need? We have all these size charts! Always order up a size if in doubt.