Archived posting to the Leica Users Group, 1997/11/29
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>Jim, you say that you need the same dpi for inkjet and other digital >printers. I have heard that it is 1/3 the dpi. Epson says 240 dpi for >the 720dpi pro stylus, the guys that do the big Novajets and others want >a 100 dpi file for their 300 dpi printers. >Not wanting someone to waste their harddrive and storage and printers >time, Steve, The 720 dpi of the Epson refers to "printer dots;" it takes a number of these to make a "cell," which is the equivalent of a halftone dot in offset printing. Imagesetters for making offset printing negs are normally at least 2500 dpi, because it takes a lot of printer dots to make a halftone dot. With either type of printer, the printer makes different tones by adding more printer dots to each halftone dot or cell. From the 240 pixels per inch that Epson recommends, I'd guess that the cell is 11 x 11 printer dots, which means that the printer is capable of printing 121 shades of each of its four colors at this resolution. Each cell is the equivalent of a pixel, but it takes a collection of printer dots to make the cell. What you want is for the number of pixels in the original image to be double (or at least 1 1/2 times) the number of cells or halftone dots in the printed image. - - Paul