I've been in contact recently with many apparel manufacturers about having blanks made to my specs. They keep asking about GSM and specifics of the meterial I want to use. I know what I want as far as cotton/poly blends, but I don't know anything about weight or thickness of the actual material. I've been researching online and also on this website and I can't find much info about it. Can you guys give me the rundown on GSM, or tell me where I can find the info? I like the softer, warn, vintage look for t's, similar to Junk Food Clothing's favorite RN0100609. If I want to have shirts made of the same weight, how do I find such info? Thanks guys. And gals.