There are many different lines that have been offered over the years by the Bud Jones company (which is part of the GPI conglomerate). They are all plastic chips, but the physical characteristics can be very different between the various lines.
I think that S2, V7, and V8 lines are the more popular for cash chips in existing casinos, and R4s are quite ubiquitous around roulette wheels everywhere.
There are sample sets available to forum members that have some of these S2 chips as well as a variety of Paulson clays. No up front cost, just sign up to receive them for evaluation. Then forward to the next interested party when you're done.