Re: [Gimp-print-devel] RE: Epson 1520 issues

[Robert L K. <rl...@al...>]

   Date: Tue, 28 Mar 2000 09:33:59 -0800
   From: David Rosky <dav...@ts...>

   Robert L Krawitz wrote:

   Another observation about 1440dpi:  When the Windows driver
   is printing in 1440x720dpi, the head moves across the page at
   about half the speed as it does in 720dpi mode.  I assume it
   does this in order to achieve the 1440dpi horizontal resolution
   using one horizontal head pass.

I *believe* that none of the printers can do 1440x720 in one pass;
they all require (at least) two passes to do it -- some printers need
four.  The fact that you're only seeing one pass of the print head is
immaterial; the head uses different jets to print each sub-pass.  That
reduces banding.  The slower print speed is simply something the
driver tells the printer to do; presumably it improves quality
somewhat.

We really need a GUI (and a system architecture) that allows the print
driver to pass arbitrary printer-specific option choices through to
the user.  PDQ does a lot of this.  It would be nice to figure out a
way to leverage PDQ or snarf some of its code (I think it's GPL).

   The upper margin of the printable area for the 1520 is supposed to 
   be 0.12".  When I place the image all the way against the top margin 
   in the gimp-print dialog box, I would expect the top edge of the 
   image to be somewhere around 0.12" from the top of the page, plus 
   or minus some amount for paper alignment errors.  With the Windows
   driver, this is generally what I get.  With the gimp-print driver,
   when using the working 720dpi microweave mode, the top
   of the image is somewhere around 0.5" to 0.75" from the top of
   the page.

That's a limitation of the driver in its current form.  I think I know
how to get rid of that, although it will make for a bit more banding
at the top, but it's going to be a fair bit of work to do.  It's
definitely something I want to fix before 3.2.  It actually might be
possible to get even closer than that, but let's do first things
first.

-- 
Robert Krawitz <rl...@al...>      http://www.tiac.net/users/rlk/

Tall Clubs International  --  http://www.tall.org/ or 1-888-IM-TALL-2
Member of the League for Programming Freedom -- mail lp...@uu...
Project lead for The Gimp Print --  http://gimp-print.sourceforge.net

"Linux doesn't dictate how I work, I dictate how Linux works."
--Eric Crampton