The DecoColor Acrylic Jumbo Paint markers work great on wood, plaster, foam, walls, paper, and terra cotta. This marker has a flat tip, providing thick and thin lines. Paint is acid-free, nontoxic, and permanent when dry. Details:BlackJumbo tip6 markersOpaque water based acrylic paintPermanent when dryPigmentedAcid free, NontoxicOdorlessKeep tightly capped when not in useStore marker horizontallyShake well before each useEasy clean up when wetConforms to ASTM D 4236