Copper. Speedball's water-soluble Block Printing Inks are brilliant, creamy-smooth, pigment rich, and offer excellent mixing qualities. Formulated for consistent drying time to maintain workability in classroom settings. Consistent tack and opacity, easy clean-up with water. Conforms to ASTM D-4236. Contains NO gluten, peanut oil, latex, wheat, dairy, eggs, glucose or dextrin.