Formulated for bold, long-lasting writing marks on whiteboards, glass and other nonporous surfaces. Ink wipes away easily with an eraser or dry cloth. Safe for use at school, office, and home. Low odor and non-toxic. ACMI Certified and Conforms to ASTM D 4236. Assorted 4Pk colors include: Black, Blue, Green, and Red. Assorted 6Pk colors include: Black, Blue, Green, Orange, Purple, and Red.