Abstract: A cartridge housing is provided for a transfer roll and an abutting ink roll. The housing inner wall is spaced closely around the transfer roll with a discontinuity in an exterior side wall that is only sufficiently wide to permit less than 90 degrees of the transfer roll outer circumference to be exposed at any one time. The exposed portion of the transfer roll abuts a print surface on a print drum. A like discontinuity in the inner housing wall around the transfer roll at a point distal from the exterior wall discontinuity permits contact with an eccentrically mounted rotatable ink roll which supplies a continuous amount of ink to the transfer roll as the transfer roll turns.