Improving printed output of digital printing systems by reduction of unprinted margins of the substrate

A pressure cylinder assembly 318 for use in a printing system 100 for transferring ink images 50 to substrate 231 from a rotating intermediate transfer member (ITM) 210 comprising a flexible belt, the pressure cylinder assembly 318 comprising:

• a. a pressure cylinder 218;
• b. first cylinder covering 219, disposed around at least a majority of the circumference of the pressure cylinder 218;
• and
• c. a second cylinder covering 375, interposed between the pressure cylinder 318 and first cylinder covering 219, and disposed around less than 5% of the circumference of the pressure cylinder 218,
• wherein a change in the local external geometry of the pressure cylinder assembly 318 due to the presence of the second cylinder covering 375 is effective to reduce a dimension of an unprinted margin 235 on a leading edge 233 of the substrate 231.

A method of operating a printing system 100 wherein ink images 50 are formed by droplet deposition upon a rotating intermediate transfer member (ITM) 210 and are subsequently transported by the ITM 210 to an impression station 216 where they are transferred to substrate 231, the impression station comprising (a) a rotatable impression cylinder 220 having an impression cylinder gap 320 housing a plurality of grippers 350 substantially recessed therein, and (b) a pressure cylinder 218 operative to rotate in the direction opposite that of the impression cylinder 220, the method comprising:

• at the impression station, applying a pressuring force between the pressure cylinder 218 and the impression cylinder 220 so as to transfer an ink image 50 from the ITM 210 to the substrate 231, such that during the transferring, a leading edge 60 of the ink image 50 is aligned with a first transfer point 340 on a surface 332 of the impression cylinder 220,
• wherein the portion of the circumference of the pressure cylinder 218 opposing the first transfer point 340 during each rotation of the impression cylinder 220 is characterized by the presence of a margin insert 375 interposed between the pressure cylinder 218 and a compressible blanket 219 disposed therearound, such that the presence of the margin insert 375 is effective to reduce a dimension of an unprinted margin 235 on a leading edge of the substrate 231.