On Fri, 11 Jun 2004 21:46:03 +0200, "Branko Vukelic" wrote:
Where can I find out the LPI of my printer? It’s a 600dpi LaserJet 1010. I want to obtain sharpest possible printouts on both plain paper and transparency. Any tips?
You will not be able to if you only read the manufacturer’s spec sheets on the device.
Laser printer manufacturers are very "oblique" when it comes to citing the maximum halftone dot frequency that their machines are capable of.
If you really want to determine the maximum dot then purchase a "Half-tone Screen Finder." This is an inexpensive plastic ruler with a calibrated section for holding against a halftone and rotating until a 4-point star appears (a moire). The moire usually appears at 45 degrees, depending on the angle that the dots are layed down on. The halftone screen value is then read off the sides. You can get one of these from: The C-Thru Ruler Co, 6 Britton Dr, Bloomfield, CT 06002. They do have a web site, but I’ve not been on it in a while.
BTW, even with PostScript laser printers, just because the printer driver says that you’ve set your halftones at 150 lines per inch does NOT mean that you will be able to print 150 out of the laser printer. As an example, with an HP Laserjet 4+ the maximum line screen you can get is approximately 127 lines per inch… but no where in the machine’s spec sheet will you be able to find this information. Talking with technical people at HP (not tech support) revealed that the reason for this is "processor power" — in other words printing a finer line screen would take more time to process and therefore reduce the "pages per minute" specs that the company wanted to shot for in its promotional materials.
And as one last tip, with laser printers there is a lot of toner splatter between the actual halftone dots and this does have unwanted the effect of "greying down" the image. So balance your need for a crisp image against the degradation that this toner splatter will cause.