Assorted Water Based Ink - 6 / SetMultisurface markers feature a multisurface ink to write on a wide variety of porous and nonporous surfaces. Durable tip resists being damaged for long-lasting use in harsh classroom environments. Nontoxic formula allows safe use by young learners. Markers are perfect for decorating cardboard, wood, glass, leather, plastic, stones, modeling clay, metal and more.