(LPI) A measure of the halftone screen. In general, the LPI of the halftone is determined by the DPI of the output device and the number of shades of grey needed (due to the need to combine printer dots into a halftone cell). A common imagesetter outputting at
1270dpi x 1270dpi can produce 256 shades of grey at 133 LPI, while a 300 dpi laser printer can only produce 14 shades of grey at 53 LPI.