Casino chips are small discs that are used instead of currency in casinos and in a virtual form online as tokens representing real cash. Chips are not to be confused with plaques which are large, high-stakes table tokens that are usually rectangular and serial numbered.
The concept of chips and plaques is the same as they are cash substitutes and hard to counterfeit. They are also easy to count and make paying a customer their winnings a simple affair.
ABS plastic is used today as the material of choice for home poker chip sets whereas casinos that once used metal chips now use a chip made from clay. Metal chips fell out of favor some time ago, mostly because of their excessive weight.
Clay chips are manufactured from a material that resembles cat litter, but is compression molded into the shape that you see today and the actual process is a highly-guarded trade secret.
The inner clay material is overlaid with a thin film of plastic applied prior to compression, giving the chip a tamperproof seal. An American casino chip weighs about 10 grams, but there is no official weight of poker chip sets.
The colors of a casino chip are significant as they usually distinguish the denomination of the chip. But there is no real standard for chip colors despite numerous efforts at chip color regulation.
For example, in Vegas a $1 chip can be found in white, blue, or gray, depending on the casino.
Outside of game play, the exonumia fraternity is a group of collectors that collect rare metal and casino-branded poker chips.
Different types of poker chips and poker chip sets have become collector's items over the years and they can be frequently seen on EBay, sometimes going for as much as $50,000.