As described elsewhere in this manual the dried state of 'conventional' inks is brought about by a combination of physical and chemical processes. Solvent-based gravure and Flexographic inks for example, dry largely by evaporation of the solvent, together with a limited degree of penetration of the substrate. The solvents will also confer properties of penetration of adhesion on a particular substate. water-based ink for the same process dry partly by evaporation followed by a chemical reaction initiated by this evaporation.