A resilient, rubber-covered roller used in an offset press's continuous-flow dampening system, in conjunction with a hard, chrome-covered transfer 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 metering roller (and/or the transfer roller) may be used as the fountain roller, or as the roller adjacent to the fountain roller. Adjusting the angle of the metering roller's contact with the transfer 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.)
In flexography, a metering roller is an alternate term for an anilox roller, a pitted metal roller used to transfer a metered film of ink from the ink fountain to the surface of the flexographic printing plate. See Anilox Roller.