They may have held paint brushes or combs. They are usually found in the sizes listed below. Some boxes have a divider and we believe they are less rare than the undivided ones. All brush boxes have flat unglazed bottoms and some collectors put small felt discs on the bottom to prevent scratching furniture. Note that all 3 boxes have the same decoration in the same places: rain cloud motif in middle of bottom, 2 parallel lines at the bottom, etc. Bottom right box has a lighter color.