Coin inlay is when you actually see a coin on the chip. The metal inserts I am talking about are the Bud JOnes chips that have metal centers that you can't see. They just give the chip weight. The inlay may be a design of some sort. For an example, you could check out the chips the WSOP uses for the higher denominations. You see no coin, but there is a metal insert in there. Correct me if I am wrong, but I think all Bud jones chips have metal centers, if they aren't CICs that is.