Yes, I'd say some color variations are close to being nothing but my imagination. Slight variation in printing and production, is a good question. Especially when the chip (as far as we know) was intended to be identical.

My personal view. Others may vary.

* molds: house vs h&c vs chipco.
yes

* distinct color variation
yes - chips, inlays, but not printing

* borders: suit, diesuit,
yes

* picture Palms A, K, Q, J
yes

* layout:
yes

* Location:
yes

* Grand Opening or limited/special edition
yes

* h&c versus long cane version
Sometimes. Paulson, it appears, uses these at random

* minor color variation
no

* lot vs rot
yes
* text: Cannery's "Las Vegas" vs "No Las Vegas" or Orleans years or Palms years.
Yes, Yes

By the way, sometimes a HS looks larger or different, when it's just at the begining of a run, stamped hotter, or harder. They are the same chips.

UV _ I've had fun, but don't get started, it will drive you MAD!

My theory is that the location, position and rotation of the H&C UV marking is a production date code, much like the tiny dates on the metal center Paulson chips.

That's why you find newer chips from the same casio all have the same UV markings, older chips are different and the really old worn chips are yet another marking.

Someone from Paulson could confirm this, without giving away the code. It would be a nice gesture to confirm that I haven't gone completly off my nut, looking at UV markings.