Vector hairlines printing poorly

[Jouni_Weckman@adobeforums.com]

ID 2.0.2
Windows XP
Canon iR 3200 PS3

I have architectural vector images made in Autocad and prepared in Adobe Illustrator 10. I have placed them into InDesign booklet and everything seems to be ok on the screen.

But when i'm printing those pages with hairlines (0,05 - 0,1mm) image quality does not meet any expectations. The weight of strokes varies e.g. in horizontal line fills. The result looks like there is overall moire effect over the line fills or the vector image is during the printing process converted to bit map image and the resolution have not been sufficient.

When I print the same image directly from Adobe Illustrator it is perfect.

I have tried everything to adjust printing settings with no success. Only thing that seems to have an effect to this is SIMULATE OVERPRINTING - when it's checked lines are printing ok but at the same time text objects made in InDesign are messed up with some kind of blur...

Thanks for your advice!
Jouni

[Geoffrey_M_Pettypiece@adobeforums.com]

When you place the Illustrator file into InDesign, are you keeping the original size? If you have a line width of 0.5 mm and then shrink it to 30%, what do you think the line width is now?

As a rule, I never print lines thinner than 0.3 mm. You can select the lines in Illustrator and change them all in one go.

[Gernot_Hoffmann@adobeforums.com]

Jouni,

if your images are not downscaled then I guess that the set-
tings (Lpi,dpi) are different for the two situations.

Can be checked by printing e.g. p.6 of this doc:
<http://www.fho-emden.de/~hoffmann/raster16052003.pdf>

There is also a "zero line width" test. This will show the
appearance of the thinnest printable lines (line width zero
is allowed in PostScript).

Best regards --Gernot Hoffmann

[Jouni_Weckman@adobeforums.com]

Hi!

All the drawings are kept in their original size.
And I have to use lines thinner than 0.3mm.

The printers printing settings are the same in both cases (ID and Illustrator) and the effect is the same with b&w laser (HP LaserJet 4000 series PS)

One thing has changed. The blur over the text objects was only in my eyes - After 50 test prints;) - so selecting the simulate overprinting has no unwanted effects.

But I still don't understand what is happening. The Color laser has over printing settings and those have no effect to the result (printer default, on, off or black text). Only thing that does is this simulation. And the ID help says that it is used to simulate overprinting if the printer doesn't do it?

Jouni

[Gernot_Hoffmann@adobeforums.com]

Jouni,

my laser QMS6100 / 1200dpi / 106Lpi / 45° can print three pairs
of lines and gaps per millimeter safely (in all directions, no
Moiré). This is equivalent to 0.15mm line width. Thinner lines
are printable, but not reliably.
Perhaps your test by Illustrator delivered thicker lines than
expected.
Overprinting shouldn´t matter for black on paper.

Best regards --Gernot Hoffmann