Before the synthetic casts took over in popularity, plaster of Paris was the primary type of cast for several decades. Fiberglass, in particular, has surpassed plaster casts in use for setting and supporting broken bones in human limbs. However, plaster casts still get a fair amount of usage because they are less expensive and more moldable around certain areas. The primary advantage fiberglass cast has over plaster casting is that it is more waterproof. As a result, a fiberglass cast requires less maintenance because it doesn’t dissolve from exposure to water. Another significant advantage of fiberglass is it dries much faster than plaster. Also, its porousness allows doctors to take X-rays of the injury with the cast on.