The Speedball Block Ink Retarder will slow down the drying process when mixed with water soluble printing inks, so you can work on your project at your own speed. It comes especially in handy when working in warm and/or dry climates. No more clogged printing screens! The retarder will not change the viscosity of your ink and is suitable for block and linoleum printing. This block ink retarder has excellent transfer tack which ensures even coverage and produces minimal odor. There is no messy clean up when using the ink base since it quickly cleans using soap and water. This ink retarder can only be mixed with water soluble printing ink. The Speedball Ink Retarder is gluten free and ACMI AP certified as nontoxic so it is safe for everyone to use both at home and in the classroom.Details:Colorless1.25 fl. oz. (37 mL)NontoxicNon-flammableSlows ink drying timeUse with block or linoleum printingClean with soap and waterOnly use with water soluble inkConforms to ASTM D-4236