and no expert (that's for sure), I would say that the very different properties of metals (coins, tokens) and "clay" and plastic mean that the wear shows very differently. My understanding is that cleaning is easily detectable on metal if you know what to look for and how to look for it. It is not so obvious on chips (coin in centers may be a different story). It is also obvious enough that if a chip shows wear but has no dirt that it has been cleaned. I also have never seen any guide suggesting that cleaned chips have reduced values. I assume that a cleaned coin does not have the same value as a similarly clean, but never cleaned chip. So, cleaning has less significance in our hobby. That being said, some are ardently against cleaning whereas others will always clean their chips. Personally, I have seen some of the people who handle chips in certain casinos, and really don't need whatever they have left behind on the chips. I don't clean older hot stamped chips or chips that look like they won't come clean anyway, but I clean most chips.

Michael Siskin