These are some of industry's top paying T-shirt affiliate programs [wikipedia]($$$). These companies products sell well, the percentages are fair, and the individual companies are reputable. To be clear, these are programs in which you can make money selling t-shirts from other clothing lines as a partnership/affiliate. This is a good method of making some extra cash on your website, especially if you don't have any t-shirt designs in the marketplace/for sell as of yet.
Top T-Shirt Affiliates:
Top T-Shirt Affiliates: