Answering a question from Dad

After my post with the pictures of the new O'Shea's chips, my father asked me via email about the colored sections along the edges of the chips. I told him that I didn't know much about that, except that they are called "inserts" by chip collectors, and apparently make the manufacturing process more difficult to duplicate by would-be counterfeiters. He replied, "I have the impression that for the same chip design, the edge markings might vary from day to day or week to week, maybe. In most of the chips I’ve seen in your blogs the edge markings seem to be pretty irregular and sometimes somewhat sloppy."

I dismissed this at first as a not very interesting observation. There always seems to be one player at the table who, out of boredom or compulsion, stacks his chips with all the edge markings lined up neatly. I've never seen chips with which one could not do that, so they must all be the same.

And they are. Pretty much. But it finally occurred to me that right now I have means to see just how identical ostensibly identical chips are. After all, I have in my possession four brand-new ones that at a glance sure look like peas in a pod.

On closer inspection, though, not so much.

First I lined up the faces to see how much offset they were, as judged by the edge markings:

This didn't surprise me. I had noticed years ago that the inserts do not have a consistent relationship to what is printed on the faces of the chips (AKA the "inlay"). I assume that this works something like mints for coins: the chips are first made as blanks, with the obverse and reverse added later, and that as a result the orientation of the inlays is essentially random with respect to the inserts.

So then I carefully lined up the dividing line between one pair of blue and lavender marks on each of my four O'Shea's chips:

If you look closely (click on photo for larger version), you can definitely see variations in the markings.

Next I carefully turned the set of chips about 120 degrees in order to photograph the next set of inserts:

There's even more variation in this set.

Finally, I did one more 120-degree rotation to capture the last set of marks:

Again, one finds easily noticeable variations from one chip to another. Not huge, but it doesn't exactly require a microscope to see the differences.

This is obviously an artifact of the manufacturing process. It's hard to find online much detail about how casino chips are made, presumably due to trade secrets and desire to keep information from counterfeiters. This Wikipedia entry tells as much as I've found anywhere, plus having a nice photo of a broken chip so you can see what its guts look like. With respect to what causes variations in the inserts, this seems to be the key passage:

The edge spots, or inserts, are not painted on; to achieve this effect, this area of the clay is removed and then replaced with clay of a different color; this can be done to each chip individually or a strip can be taken out of a cylindrical block of material and replaced with the alternate color before the block is cut into chips.

So now you know as much as I do about the whole matter--which isn't a lot, but maybe more than you knew five minutes ago.