Printing very narrow lines

Hello,

I need to print very narrow lines, i.e. between 10 and 40 microns
wide, from an AutoCAD drawing. Therefore I've defined a plotstyle
table and applied the styles to the adjacent layers. I checked the
"print with plot styles" option in the Autocad print dialog and set
the Distiller printer to the maximum resolution (4000dpi).

However, when I print them to a PostScript or PDF file and have a
close look at it, all the lines seem to be a lot wider, about 200
microns.

Is it possible to get lines below 200 microns in a PostScript or PDF
file at all?

I'm using Autocad 2002 and Distiller 6.0.1 on Windows XP.

Thanks for any helpful adivce!


Regards,
Johannes

 

Yes, in both of them. See the file thinlines.{pdf,ps} here

http://www-user.tu-chemnitz.de/~ralk/latex/pdfthinlines/

(made with pdfLaTeX) with lines from 1000 microns to 1 micron. Adobe
Reader 6.0 supports zooming upto 6400%, here's what you need it for. You
will evt. also see effects of limited screen resolution if you did not
zoom in enough.

Remember to disable "Fit to Page" in Acrobat Reader, when printing the PDF.

Printed to a HP Color LaserJet 4500 (600 dpi), the last "step" is
between 20 and 10 microns.
On a HP LaserJet 4M Plus (600 dpi as well) the last step is from 40 to
30 microns.
On an old HP LJ 4 ML (300 dpi), the last step is from 75 to 50 microns.

In all cases, after this "last step" the lines are of equal width in the
printed result, so all the lines after this step are too thick in
absolute terms.

All in all, the 4500 produces the finest lines, comparing the results
visually.

Have a look at the specs to get the true minimum. But I guess they did
not specify one, as there is no theoretical one. Practically however,
the minimum depends on the resolution of the device to print on. So, do
the math, e.g. a 10 micron line is about 1 single dot wide on a 2400 dpi
image setter. From that perspective the 4000 dpi you selected should be
more than enough to get it right. Nevertheless you will experience
quantization errors, even in 4000 dpi.

At 4000 dpi

40 microns = 6.3 dots is rounded to 6 dots
30 microns = 4.7 dots is rounded to 5 dots
20 microns = 3.15 dots is rounded to 3 dots
10 microns = 1.57 dots is rounded to 2 dots.

For example, you see the 20 micron line is not double as wide as the 10
micron line.

I'm just curios what you need such fine resolution for, do you want to
prepare masks for semiconductors or what?

The Distiller might have some option hidden somewhere where you can set
a minimum line width. And try with another program to see, whether the
problem is with AutoCAD or Distiller.

Hope, this helped.

Ralf