Stussy and Supreme have cut and sew blanks meaning they make their t shirts from scratch which is why they are such good quality and fitAlso, you'll find most major brands use Alstyle blanks, aside from Supreme, Stussy, and a few others.
Do you know what Stussy use? I've had a lot of different t-shirts, but the fit of Supreme and Stussy are the best i've had. Stussy's a bit loose(the one i have) than Supreme but the fabric feels the same.
By the way i have some raglans from Augusta. They're really thin and not baggy. I don't like its fit since i like them baggy, but i'm just letting you know if y'all like it like that..