Educated guess. So I decided to do some checking.
So I did some checking and couldn't find anything. So I was able to get some professional legal advice from a real patent and trademark attorney!
She says that there are no laws against relabeling any brand of clothing and selling it as your own, or keeping the original label, then adding your embellishments to it and selling it. That is the reason people are able to use the blanks they use for printing. No laws against it.
The trouble comes in when people use garments and "add" a label that's protected by someone else. For instance, I can't take an old navy shirt relabel it with a hanes label and sell it to someone as hanes, because I'm not hanes. Fraud. But I can take an old navy shirt, relabel it with a brand I own, and call it my brand.
The brand you use makes no difference because there are no laws relating to it. Even if the original company doesn't like it, there's nothing they can do about it.
I guess it never really comes up when you talk about brands like Old Navy, Gap, etc. is because you can't really get those brands wholesale. You'd be paying an arm and a leg for shirts, when you could find another wholesale brand alot cheaper, thereby making more money.
I'm pretty sure those brands don't like the idea of people doing that and that may be why you can't get wholesale pricing on them.
