Robinson Ransbottom, aka RRP Roseville Pottery Co., of Roseville, Ohio. RRP started in business before 1900, and has just recently gone out of business. They were one of American's great old pottery companies that made stoneware, spongeware, art pottery, vases, planters, birdbath inserts, dinnerware, cookie jars, etc. All RRP is collectible, especially now that they have closed. Their pottery is heavy, well-made, attractive, durable, affordable, and quite functional. Check my Kitchen Collectibles categories for more great RRP items!
RRP Roseville as it is commonly known, is not the same as the Roseville Pottery Co.; they were two separate companies, both formerly doing business in Roseville, Ohio, and both companies are now out of business.
Lay people tend to lump them together, but they are not the same. Roseville Pottery tended to produce more decorative and expensive Art Pottery, while RRP Roseville tended to produce more utilitarian items, although, they also produced some Art Pottery.