A hard, chrome-covered roller used in an offset press's continuous-flow dampening system, in conjunction with a soft, rubber-covered metering roller. The line of contact between the two rollers, called the metering nip can be varied in width, depending on the desired thickness of the film of fountain solution. The transfer roller (and/or the metering roller) may be used as the fountain roller, or as the roller adjacent to the fountain roller. Adjusting the angle of the transfer roller's contact with the metering roller varies the thickness of the fountain solution film across the length of the rollers, depending on whether the edges or the center of the plate require greater quantities of fountain solution. (See Dampening System.)
The term transfer roller also refers to a rubber-covered roller or cylinder used offset gravure printing, which is a type of gravure printing utilizing a blanket similar to that used in offset lithography. In offset gravure, the image is transferred from a gravure cylinder to the rubber transfer roller and, finally, onto the substrate. (See Gravure: Offset Gravure.)