Inkjet CTP method for preparing a set of lithographic printing plates

A method of preparing a first lithographic printing plate and a second lithographic printing plate for lithographic printing of a color digital image on a receiver wherein the color digital image includes a plurality of colorant separations, the method comprising the steps of:

• jetting droplets with an inkjet CTP system on a first lithographic support of the first lithographic printing plate to form a printing area of a first lithographic image that represents a first colorant separation of the plurality of colorant separations;
• jetting droplets with the inkjet CTP system on a second lithographic support of the second lithographic printing plate to form a printing area of a second lithographic image that represents a second colorant separation of the plurality of colorant separations;
• forming a portion of the first lithographic image and a portion of the second lithographic image in a same print pass by an inkjet printing device of the inkjet CTP system;
• feeding the first lithographic support and the second lithographic support onto a printing support of the inkjet CTP system;
• aligning the first lithographic support and the second lithographic support to be parallel to each other;
• and
• prior to the step of jetting the droplets, performing the steps of:
• measuring a position of the first lithographic support and the second lithographic support on the printing support;
• and
• merging the first colorant separation and the second colorant separation into a digital image in accordance with the measured positions;
• and
• halftoning the digital image to a digital raster image.