Plaster is the traditional and historic material for ceiling domes and rings and has crisper edges and better defined ornamental detail verses other products that are now on the market. While most smaller Castle Design domes are crafted with decorative rings attached, our larger styles are available without rings. By offering rings in Classic, Traditional and Victorian syles separately from the domes, you can choose between ornate and plain rings on several of our larger dome offerings. View our portfolio of installed plaster ceiling rings. Installation.