Speedball 3449 Ink Extender For Water-Soluble Block Printing Inks AP Certified 1.25 FL OZ SUBTLE TRANSPARENT COLORS  Mix with Speedball Water-Soluble Block Printing Ink to create subtle transparent colors for your relief prints. Simply apply a small amount of ink to the base and thoroughly mix for a gorgeous, streak free result. MAINTAINS VISCOSITY  The viscosity of your block printing ink will not be affected when using the water-soluble block printing ink extender, so you will produce consistent results every time. QUICK, EASY CLEAN UP  Clean up is fast and easy. When you are done with your project the extender and ink will come right off you using soap and water. AP CERTIFIED  The Speedball Water-Soluble Block Printing Ink Extender is ACMI AP Certified, so it is safe for everyone to use both at home and in the classroom.