Midori Paintable Self-Inked Rotating Date Stamp - StationeryThe stamp is self inked with black oil based ink which you can stamp approx. 1,000 times without refilling ink. The ink is oil based waterproof, it dries fast, you can color in and around the design without worrying about smearing the stamped ink. The design of the frame is stationery design, and by rotating the date parts in the center, you can change the date, month, and some icons such as weather, faces etc.