There is disclosed a selective wetting apparatus comprising a roller rotatable about a roller axis and comprising a wettable roller surface; an applicator unit having a lip which extends parallel to the roller axis and is radially spaced apart from the roller surface by a gap, wherein the applicator unit is to convey liquid agent towards the roller so that the liquid agent forms a liquid bridge over the gap to wet a wetted axial portion of the roller surface; and a flow guide to direct a gas flow into a regulated axial portion of the gap to locally prevent formation of a liquid bridge, and thereby prevent wetting of a corresponding axial portion of the roller surface.

There is disclosed a selective wetting apparatus (2) comprising a roller (20) rotatable about a roller axis (24) and comprising a wettable roller surface (22); an applicator unit (10) having a lip (12) which extends parallel to the roller axis (24) and is radially spaced apart from the roller surface (22) by a gap (30), wherein the applicator unit (10) is to convey liquid agent (14) towards the roller (20) so that the liquid agent (14) forms a liquid bridge (32) over the gap (30) to wet a wettable axial portion of the roller surface (22); and a flow guide (50) to direct a gas flow (56) into a regulated axial portion of the gap (30) to locally prevent formation of a liquid bridge (32), and thereby prevent wetting of a corresponding axial portion of the roller surface (22).

A removable flexible jacket for use in a printing press having a transfer cylinder for transferring a freshly printed substrate comprises a sheet of woven fabric, a beaded film sheet coupled to the sheet of woven fabric, and an image disposed between the sheet of woven fabric and the beaded film sheet. The image is visible through the beaded film sheet, and wherein the image divides at least a portion of a surface of the beaded film sheet into a plurality of zones.