Any die that does not meet specs for some reason gets a factory cancel mark, Is stamped with a logo, and trown in the bin to be sold as a souviner. Check out Gamblers General Store. They have a large bin of casino dice, most of which will have a "VOID" pressed into the 4 side. On close inspection many of these dice can be seen to be unfinished (raised gold logo, machining marks, missing spots, ect) Often the logo stamped on Rejects/Culls is from a defunct casino as the factory still has the stamps. I have seen lots of rejects with multiple logos stamped on them and overstamped logos as well. As far as sendind dice out, T.J. Wholesale in Vegas used to buy dice from the casinos and put a gold hotstamp contour bar on the 6 side, then resell them. I have several pairs of Tahoe dice from them.