I think the term you want to use is "blanks". There are several online sources for them. I don't know if you want adult or children's sizes. I sew for my kids so I only really know about good sources for childrens. I buy most of mine from American Apparel. If you have a wholesale license their pricing is very reasonable ($3.50-5 for children's blanks) However if you don't have one then the price isn't very good. They are sweatshop free which is a plus for me. I've been really happy with the ones I've gotten from them. Don't care much for the look of their website, last time I logged on to order I thought I'd gone to a porn site buy accident, but I guess they are hot company right now.

If you want children's I have a couple other sources bookmarked I can look up for you.

HTH!
Tanya

Here is a link that might be useful: American Apparel