A recording material (ink) showing a selective adhesiveness to one of a pair of electrodes applying a voltage to the recording material, is constituted by dissolving an electrolyte in a solvent. The recording material is provided with an improved stability against environmental changes, particularly against a humidity change, if the solvent is at least partly constituted by a reaction product between a ring-opening product of an alkylene oxide R--O.sub.n and glycerin or phenol, wherein R is an alkylene group and n is an integer.