OSX - cannot print thin lines/close hatches

[Anonymous]

Hi,

We have been unable to print narrow lines (from 0.13mm to about 0.35 mm) since moving to OSX.

Attached is a screen shot of two sections of wall, the right one in an ArchiCAD window, and left one in an Acrobat reader window.

The PDF version in the Acrobat window was generated from the wall in the ArchiCAD window next to it.

When we Plot from ArchiCAD/Plotmaker, the plotted image is generated directly from the ArchiCAD/Plotmaker file and the output matches what is seen on screen (right image). This is also what we get printing from OS9.

However, when we Print (to any printer) it appears that the printed output is generated from the PDF/Quartz image which gives a poor output as seen in the Acrobat window (left).

See how the narrow lines become thickened, and the close hatched lines merge into one thick line.

Please can other OSX users compare thin lines Plotted and Printed from the same file and see if this is a general problem, which I now suspect, after careful investigating/testing. Thanks.

(Same for various Apple Mac G4s, G5s OS10.3.4/5 1Gb RAM, ArchiCAD 7, 8 and 9.)

If you wish for a higher resolution JPEG, please leave a private message.

Regards,

Nick Harvey

[__archiben]

are you sure it's not just the resolution of your 'print' that's causing it?


~/archiben

[Anonymous]

Hi,

Using the same version of Plotmaker (2.3 V3), Epson 3000 printer same 720 DPI print setting, same paper, same everything else, I printed a drawing from Plotmaker under OSX and OS9 Classic.

I then scanned the same section of each printed drawing at 2400DPI

Plotmaker OSX – PM 2.3 v3 OSX2.tif - Narrow lines are enlarged

Plotmaker OS9 Classic - PM 2.3 v3 OS9 Classic2.tif - Narrow lines print correctly and match as shown on display

It is the same from all versions of Plotmaker run under OSX including the version shipping with ArchiCAD 9 – narrow lines get enlarged when printed, but not when plotted.

It occurred to me to calculate the pixel size of the two scans in order to work out in mm the actual line thickness printed.

At 2400 DPI which the scans we done, 1 pixel = 0.010583mm

Counting the pixels on a line set at 0.13mm (smallest - pen 1- used on door swings, kitchen units, windows) gives:

PM 2.3 v3 OS9 Classic2.tif about 1.3mm which is correct

PM 2.3 v3 OSX2.tif about 0.25mm which is nearly twice what is should be!

Please can someone else try this.

Regards,

Nick Harvey

[Anonymous]

I believe that this is part of the old Plot vs Postscript problem.

In OS9 the basic print engine is Quickdraw which prints lines at their precise, technical weight, the same as plotting.

Postscript has always "known better" what we want and tends to thicken fine lines to try to remove the appearance of stair stepping. This was true in OS9 when printing to a Postscript device. I once "upgraded" a Quickdraw printer to Postscript and was so unhappy with the results that I convinced the vendor to take it back.

Quartz has now replaced Quickdraw with the new underlying PDF display/print engine which is in turn based on postscript. Thus the problem in OSX.

There is no going back to Quickdraw and HPGL is slowly fading into oblivion, so we need to figure out (eventually at least) how to get decent results from Quartz/PDF (this also affects Windows users who want to use PDF for sending docs to clients and service bureaus, and for archiving).

I have found that the problem is much less with higher resolution printers. The printer I returned was an old 300dpi laser. The newer 1200dpi machines don't seem to have much of a problem. Your example from the Epson 3000 seems so extreme that I have to wonder if there is something else going on.

I have found with some clients that reducing the finer line weights for Postscript/PDF output helps considerably. You might give that a try. It may also depend on the specific printer, so I can't be sure.