Abstract: The present invention provides an aqueous dry-erasable ink or marking composition, which could be applied to both porous and non-porous surfaces and erasable from both porous and non-porous surfaces or marking substrates. The present invention further provides erasure of mark made by the ink composition from such porous and non-porous substrate, which is achieved by a cloth or the like, without requiring rubbing by conventional erasers. The ink composition comprises water, composite pigment, one or more rheology additive, one or more wetting agent, one or more water-soluble resin, pH adjuster and one or more biocide. The composite pigment is a compound of polymer resin and colored pigment at a weight ratio from 10/90 to 97/3.

Abstract: The present invention provides an aqueous dry-erasable ink or marking composition, which could be applied to both porous and non-porous surfaces and erasable from both porous and non-porous surfaces or marking substrates. The present invention further provides erasure of mark made by the ink composition from such porous and non-porous substrate, which is achieved by a cloth or the like, without requiring rubbing by conventional erasers. The ink composition comprises water, composite pigment, one or more rheology additive, one or more wetting agent, one or more water-soluble resin, pH adjuster and one or more biocide. The composite pigment is a compound of polymer resin and colored pigment at a weight ratio from 10/90 to 97/3.