OSX can not print line thicknesses correctly

[Anonymous]

Hello,

I have now completed some tests and it appears that OSX can not print line thicknesses correctly (G5 OSX 10.3.9 ArchiCAD/Plotmaker 9 - printing, not plotting).

Set up a test page with 100% black lines on a red background (colour not important):

0.13mm wide lines at 0.26mm C/C as stripes, and also as a grid of squares.
0.25mm wide lines at 0.5mm C/C as stripes, and also as a grid of squares.
0.35mm wide lines at 0.7mm C/C as stripes, and also as a grid of squares.
0.5mm wide lines at 1.0mm C/C as stripes, and also as a grid of squares.

This should give a series of lines with gaps equal to the width of the lines.

Print (not Plot) and the scan the results at, say, 1200DPI.

Counting the pixels gives the line/gap widths, which in any case should be equal. Counting the pixels will give a true line width, in this case 25.4mm/1200DPI should give the pixel size in mm.

However, non of the large format printers I have tested print the line thicknesses correctly. All make the lines thicker, the best 50%, the worst 100%. In the worst case the stripes disappear into a black mass!

Please can other Mac users test their large format printers as above and report here. Am I alone in wanting my 0.13mm lines to be 0.13mm, and not 0.25mm?

Regards,

Nick Harvey

[TomWaltz]

My experience with Kip Star Print series on OS 10.2, 10.3, and 10.4 has been that the line weight print or plot exactly as I've set them to.

I did have some issued with gray-scale lines some time back that was a plotter driver issue, not an OS X issue.

[Anonymous]

Printing with Postscript has always tended to fatten lines. I thought this had been largely fixed with higher res printers but I guess not. In my experience non-Postscript printers have always been pretty accurate with their lineweights. Mac OSX uses PDF (based on Postscript) as its core display/print technology. Perhaps this complicates matters. It would be interesting to see the result from various printers.

EDIT:

You got me thinking further about this so I drew up a quick test file and printed it on my nearest printer. I don't think there is any need for the cross hatches since the parallel lines seem to do the same job, but I added radial lines and 50% grays to see what would happen. On the first pass any driver issues were overshadowed by obvious bleeding on the cheap paper, and I have to install new Mactel drivers before I can test on better stock.

The test file is attached for anyone who wants to try it on their own machines.

[Anonymous]

I think this is a print driver problem. We have noted the same problems on the HP plotters we have used (1055cm and 4000). When PRINTING the lines are a muddy mess of lineweights. PLOTTING works fine.

Print the same file to pdf or to a laserprinter and the lineweights come out right.

I don't think HP is going to write decent drivers any time soon...

[Anonymous]

In case anyone is interested...

Since the smaller pen sizes don't seem to print well at spacings of double their width, I split the test patches to print half at quadruple the line weight. I have also added circles to show where the radial lines merge for comparison to the printed results. I have attached the changes as a module since the PLN got too big.

[Anonymous]

Hi,

Have just done a Print/Plot test from Plotmaker 9 to an HP Designjet 800 (not Postscript)

Plotting using the built in Plotmaker plotter driver works fine.

Printing using the current HP Designet 4.1 driver is just horrible!

To see the samples (1.3mb), download them from:

http://www.bigupload.com/d=9CA63C9E

Hope this is of interest.

Nick

[Anonymous]

I ran some more tests on my handy Canon MP780 and found that the line weights are pretty consistently about 0.1mm thicket than they should be. I'll try it on some more printers/plotters when I get the chance.