I am often asked what “bonded bronze” and “bonded marble” (or, for that matter, “cold cast” marble, bronze, etc.) are. Be aware that they are not real bronze, or stone. I consider these to be a faux finish on plastic resin, since they are made by mixing bronze or marble powder with the first (and very thin) layer of resin when casting polyurethane or other resins in a mold. They are not weatherproof, since polyurethane resin degrades when exposed to UV radiation or even seasonal (think: midwestern) temperature fluctuations. Nor are they very sturdy (treated carefully, most of my plaster pieces have actually held up better over time).
So, buyer beware. That inexpensive “real” bronze sculpture may not be what you think.