The term acrylic is used for products that contain a substance derived from acrylic acid or a related compound. Most often, it is used to describe a clear, glass-like plastic known as poly(methyl) methacrylate (PMMA).he term acrylic is used for products that contain a substance derived from acrylic acid or a related compound. Most often, it is used to describe a clear, glass-like plastic known as poly(methyl) methacrylate (PMMA).