To facilitate the adjustment of ink concentration.

The inking unit for a printer comprises a calling roller 16 reciprocating between an ink fountain roller and a deflection roller 15 which is axially reciprocatingly movable so as to be alternately brought into contact with both the rollers. The rollers 15 and 16 are reciprocated so that periods of periodic motions are different with respect to rotation of a plate cylinder 2. For example, the roller 15 reciprocates one revolution in an axial direction per three revolutions of the cylinder 2, and the roller 16 reciprocates one revolution between both the rollers per two revolutions of the cylinder 2.