In a classic general sense, each gambling supply house would have one or more exclusive rim mold designs that all its customers would have to use on "protected orders" whereby the supply house would keep records and only use the monogram you selected only for you. That is, only you could re-order chips of that design on that mold.

For example, I once acquired a box of the chip below. I auction off some chips under this title: "New find: 1944 illegal club chip of Benny Binion's Southland Hotel. Identified thru manufacturer's records." That ivy Miller on the card worked for Binion. Only Ivy Miller or someone known to be authorized by him or the Binion organization could reorder the same design on that harp mold.

Some more on molds on my page here:
http://www.antiquegamblingchips.com/molddesignindex_site.htm

Robert