Option pads feature removable color pads within each pad for expanded versatility. Ideal for creating various color spectrum and direct-to-paper techniques. Also easy to clean and re-ink. Colorbox pigment pads are water based and formulated to stamp on absorbent papers. Slow drying inks are rich thick fade resistant non-bleeding acid free and archival. The ink surface is raised for optimum results on any size stamp. Stackable. Non-toxic. ASTM D4236 approved.