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. ASTM D4236 approved. Non-toxic. Includes 8 colors. Size of each color pad: approximately 2-inch by 1-1/2-inch.