An example method comprises identifying, by a processor, a gap in a housing of a printing apparatus and positioning an inlet of a conduit inside the housing proximate the gap. The inlet is fluidly connected to a fan, and the fan is powered to create a pressure differential across the housing to minimize the amount of air inside the housing being able to escape the housing via the gap.

A flexographic printer is provided with: a printing plate for transferring ink at an ink transfer site to an object to be printed S; an anilox roll for supplying ink to the printing plate at an ink supply site; a plate cylinder on which the printing plate is wound and rotated; and an ink solvent supply unit for supplying a solvent for the ink on the surface of the printing plate in a post-ink transfer region that is downstream of the ink transfer site in the plate cylinder rotation direction and upstream of the ink supply site in the plate cylinder rotation direction.

An example method comprises identifying, by a processor, a gap in a housing of a printing apparatus and positioning an inlet of a conduit inside the housing proximate the gap. The inlet is fluidly connected to a fan, and the fan is powered to create a pressure differential across the housing to minimize the amount of air inside the housing being able to escape the housing via the gap.

A seal member includes an annular seal body extending about a flow axis. The seal body has a first sealing face, second sealing face, and a step face. The first sealing face extends radially from the flow axis and has a planar contour. The second sealing face extends radially from the flow axis, is axially opposite the first sealing face, and has an arcuate contour. The step face extends radially from the flow axis and is defined axially between the first sealing face and the second sealing face, the step face arranged for capture between a spout and a reservoir body to capture the seal member. Fluid reservoirs and methods of making fluid reservoirs are also described.

A flexographic printer is provided with: a printing plate for transferring ink at an ink transfer site to an object to be printed S; an anilox roll for supplying ink to the printing plate at an ink supply site; a plate cylinder on which the printing plate is wound and rotated; and an ink solvent supply unit for supplying a solvent for the ink on the surface of the printing plate in a post-ink transfer region that is downstream of the ink transfer site in the plate cylinder rotation direction and upstream of the ink supply site in the plate cylinder rotation direction.

A printing cylinder includes a plurality of suction chambers and a masking sheet configured to cover the suction chambers. The masking sheet includes a non-sucking portion which protrudes from the boundary of the suction chambers toward the inside of the suction chambers. A number of through holes are formed in a portion except for the non-sucking portion in the masking sheet. The non-sucking portion exists between the sheet to be printed and the boundary of the suction chamber to be used and the suction chamber not to be used. This can prevent an ink mist from adhering to the printing cylinder.