"A chip on the table for three months will look different from a chip on the table for 3 years. Again, I don't say that I have the answer, but there are definitely numerous chips that fall between these two conditions, better than "Average", yet not quite nice enough to be called "Slightly Used"."

I think that you may be going in the wrong direction of the grading guide Jerry. Instead of grading UP for a chip that has been on the tables for 3 years ... perhaps you should be grading DOWN to "Well Used"!

Wear is wear. Some casinos, such as in Las Vegas and/or Atlantic City, will get far more use from their chips due to the sheer volume of play as opposed to a much smaller gambling venue or a property that is only open at certain hours of the day/night.

See link below ...