Washable Tricolor Rainbow Stamp Pad Primary ColorsThis washable tricolor rainbow stamp pad is perfect for rubber stamps and for decorating with child hand prints and mementos. Features three primary colors: Red, Yellow, and Blue. The dye-based, unscented ink is completely child safe, non-toxic, acid-free, and archival quality. Measures 2" x 2". Conforms to ASTM D-4236.