The chips are made of a light, but durable plastic that I feel will last a long time, especially with my intended use. Also note the chips are not magnetic to each other. Although I'm storing my chips in a different container, the reusable plastic bag is an excellent storage option and is tightly sealed.NOTE: Even though the item is described as having 100 chips, the reusable plastic bag states that the actual number of chips is an approximation. Be sure to count the chips so that you have the desired amount. This item came with 98 chips, however, the amounts of other colors of chips I have purchased in the 100 chip series have been different, more or less. The red chips look similar to the pink chips, so be careful if you want to keep them separated.