Erasable system including marking surface and erasable ink composition

An erasable system including a marking element and an erasable marking composition for applying markings to the marking element, said marking element comprising a plurality of superposed sheets bound in the form of a book, each sheet comprising a non-porous marking surface comprising a polymeric material carried by a substrate, said marking composition consisting essentially of an aqueous dispersion of a particulate, polymeric film-forming material, a colorant, and an amount of a polymeric shear-thinning material sufficient to provide an erasable marking composition having a shear-thinning index between about 0.01 to about 0.6, said marking composition having a viscosity of about 100 cPs or lower when measured at a shear rate of 300 reciprocal seconds and providing a coalesced residue on drying which is substantially water insoluble and which can be completely erased from the marking surface with an elastomeric eraser.