I've done this but from jiffyshirts.com. I usually would purchase the Gildan brand but they would end up shrinking overtime. Which is better, 3 shirts at $3 that shrink overtime or 1 shirt at $15 ?
I think the key is to find something that is not 100% cotton but rather 50% cotton/50% polyester. Looking at the material difference between the shirts I've purchased, the Gildan heather colors are 50/50 where as the the other colors are either 100% cotton or 90/10. By comparison, the Dickies heavyweight and Carhartt heavyweight are 50/50 and 60/40 material.
I think the key is to find something that is not 100% cotton but rather 50% cotton/50% polyester. Looking at the material difference between the shirts I've purchased, the Gildan heather colors are 50/50 where as the the other colors are either 100% cotton or 90/10. By comparison, the Dickies heavyweight and Carhartt heavyweight are 50/50 and 60/40 material.