An ink which can cause a change in its adhesiveness by an electrochemical reaction is obtained by impregnating a crosslinked substance such as polyvinyl alcohol with a liquid dispersion medium comprising an organic solvent having a relative dielectric constant of 15 or larger at 25.degree. C. such as ethylene glycol. The ink shows little characteristic change due to drying, etc., and suitably retains its fluidity when left standing in the air for a long period. The ink is supplied with a pattern of energy to be provided with an adhesive pattern, which is then transferred to a recording medium such as plain paper, directly or by the medium of an intermediate transfer medium to form an ink pattern corresponding to the energy pattern applied.