As an adjective, the word “plastic” means pliable or able to be molded and formed. Therefore, plaster is defined as a type of plastic material, but not a material made out of what we now refer to as plastic. Confused yet” To confuse you even further, you can use the term plaster to refer to the material when it’s dry (as a powder), when it’s wet (as a liquid), and when it’s hard and dry (as a solid, of course). And, to make it worse, there are many types of plaster, all dependent on their respective ingredients. FYI: Most things called plaster are actually gypsum plasters. We’re not going to get into all of the details here, but we will name off some other kinds of just so you’ll recognize the names: Gesso; Stucco; Lime Plaster; Whitewash (really more like a paint); Clay Plaster; Calcium Plaster; Venetian Plaster (really more of a surfacing technique); and Plaster of Paris (remember this from summer camp”).