Here is a copy of one of my post I made here on a private part of the forum (so some people probably didn't see it), after some of you bought some press discs on eBay, marked as "possibly a Proto or Beta" by the seller. this information is about press discs for the Sega Saturn. So, press discs ARE retail discs without a label, nothing more (99% of the time). I hope this information will be useful and that you will never bought (again) some fake proto/beta discs.
White Label disc for DC are really common compared to Saturn press discs, so people already know about White Label disc but NOT about the Saturn press discs, otherwise people will never buy them thinking there are proto/beta;-)
I could have confirmed this. Most press builds are either shipped on commercial discs without any artwork or box, or sent on a CDr or DVDr. I have several of both from doing reviews over the years.