PURPOSE: To obtain an ink compsn. which is suitable for single-color coloration and decorative printing and forms a coating film excellent in colorability, adhesive properties, and solvent resistance by compounding an ethylenically unsatd. monomer, a synthetic resin, a pigment, an org. solvent, and other additives.

CONSTITUTION: This ink compsn. having a solubility parameter of 9-14 [cal/ cm3]1/2 is prepd. by mixing and stirring 0.5-40.0wt.% at least one ethylenically unsaid. monomer selected from among diallyl phthalate, styrene, and a (meth) acrylic ester, 0.5-30.0wt.% at least one synthetic resin selected from among an unsatd. polyester resin, a diallyl phthalate resin, an acrylic resin, a polyamide resin, a ketone resin, etc., 0.5-40.0wt.% org. or inorg. pigment, 45.0-90.0wt.% org. solvent, and optionally 0-2.0wt.% dispersant and 0-2.0wt.% other additives.