The impact-modified acrylic resin may be a copolymer, e.g. methyl methacrylate polymerized with another monomer such as methyl acrylate, ethyl acrylate, butyl acrylate, acrylonitrile, styrene, or butadiene; a terpolymer or multi-polymer made from three or more of such monomers; or a blend of methyl methacrylate with elastomer, vinyl, or other modifiers.