The protocol uses a short initialization sequence to set up the printer and load a page. After that, bit patterns with their own header are sent to the printer, usually followed by a sequence to transport the paper to the next vertical position. The bit patterns have one bit for each pen in the cartridge. Certain bytes in the header set the horizontal start position and the number of columns to print. A checksum, the complete number of bytes for one sweep including the header, has to be present in the header to make the printer accept the data.
Color printing is nonetheless a difficult issue.
As there are three colors in the color cartridge, there is only a third of the pens available for each color. Yet all three colors are printed in one sweep, so there have to be some arithmetics. Optimization of white spaces is also handled by this driver by reducing the sweeps to their minimum width and transporting vertically over completely empty lines in just one sequence. The driver filters GhostScript output to the Lexmark protocol. The input format is bitcmyk.