SpreadShirt, Zazzle and CafePress, all allow you to print t-shirts without keeping inventory. The profit margin is not large, but it is still good, considering

SpreadShirt, Zazzle and CafePress, all allow you to print t-shirts without keeping inventory. The profit margin is not large, but it is still good, considering you just have to focus on the design only. You have to consider the materials of the t-shirts used, seems like most of the folks like t-shirts printed using American Apparel t-shirts.