Prang Decor Multi-Surface Art/Craft Markers, Medium Tip, 6-Color Set (74006) Opaque water based inks Durable medium tips for decorating cardboard, wood, glass, leather, plastic, stones, DAS modeling clay, metal and more Permanent results on porous surfaces Set of 6 bright colors: Yellow, Red, Green, Blue, Black, White AP Certified non-toxic and conforms to ASTM D4236 standards