I was mailed the chip pictured below. The person who sent it thought it might be a new code. The center has a shallow recess, and there is fine cross-hatching in that recessed part (like a fine linen finish).

I don't think it is a new design of a generic poker chip. I think an inlay was there; it is missing now (notice the nicks where a knife may have helped pry the inlay off); and the inlay caused the cross-hatching.

Can anyone answer these questions:
(1) chips weren't made with recessions, then cooled and hardened, and then inlays would be added days later to these chips (glued into the cold chip)?
(2) at what time were the inlays added-- at the very start with the soupy clay, or when the clay was putty-like? In another words, was the chip prepared (compressed) before the inlay was placed on and pressed in the chip mold? Any articles on this?
(3) I note that there is cross-hatching in the clay where the inlay goes. Did the cross-hatching come from the inlay? Was the cross-hatching made in the mold as the chip was prepared for the inlay?
(4) the link below might aide the discussion.
thanks,
Robert