salt glaze color with 2 blue stripes around and the bottom of the tumbler. The mark is pressed into the bottom not printed. Can you tell me anything about them? Are they rare? I can not find a mention anywhere. If it helps I can post a photo.
The pottery was made by Robinson Ransbottom Pottery, formerly of Ironspot (just outside Roseville), Ohio. They went out of business a few years ago but pieces are still available at retail pottery outlets.