This can be a challenge for most printers if you are using a pin registration system or are producing plates with a straight cut across the width of your plate. The solution, while simple, can be a challenge for printers using the above methods of mounting their plates as it entails stepping the image either up and down or stepping the image progressively down as you step and repeat it across the width of your web. This will then require you to cut your plates in the same stepped manner and can make mounting quite a challenge and eliminates the option of using a conventional pinned system.
The reason for the stepping of the image is to minimize the possibility of a continous gap occuring on any or all of the colors across the web. This means that some part of the image should be in contact with the web, which in turn will be pressed against the impression roll. This in turn will reduce the bounce and hence vibration that can often be seen and even heard at press side when the printed edge finishes in a straight line.
One method of overcoming these mounting challenges is to have the design engraved as a continous engraving, i.e. ITR, which can be produced in elastomer by direct laser ablation or as thermally ablated or chemically washed continous polymer sleeves.