1. A printer comprising a printing unit arranged to produce a printout from image-representing print data of an image to be printed, and a processing unit for processing image-representing input data of the image so as to generate the image-representing print data, wherein the processing unit is arranged for: separating the image into a line detail sub-image containing edge and line details, and an area detail sub-image containing area details; performing a first printing mode processing pipeline on the line detail sub-image and performing a second, different printing mode processing pipeline on the area detail sub-image; and generating multi-layer print mask data, wherein at least one print mask data layer is usable to print the line detail sub-image in at least one line detail print pass, and the remaining, at least one, of the print mask data layers being used to print the area detail sub-image in at least one area detail print pass.