Sorry for the delay in posting this info. Thanks for the patience...
-open recent dwg file
-choose layout (A1, A2, A3, etc.)
-file drop-down, choose print
-in Print screen
choose plotter (HP DesignJet 450c)
paper size ARCH D 24 x 36 inches
click Edit Page Setup
-in Page Setup screen
Use available page setup: unchecked
Paper Size: ArchD
What to Print: Layout
-in Print - Advanced screen
Plot Style Table: monochrome.ctb (print with plot styles checked)
Plot Offset: X = 0.00000, Y = 0.00000
3D Viewports: Shading = grayed out, Quality = Normal, DPI = grayed out
Plot Stamp: Include plot stamp = unchecked
Print Options: Print paperspace last= checked
Sharing: Save device settings to: = unchecked
click OK on Page Setup screen
-back at Print screen
Paper Size now says "Super A1 24x36"
clicking Preview in either landscape or portrait cuts off 12" or so of 36x24 layout
clicking Print does same thing (of course)
I've done everything according to your way and get acceptable results.
Apparently the case in the settings of the printer-plotter in System Preferences.
Try again to install the printer via System Preferences.
I've been doing it this way:
1. Add printer with "fake" IP address(3) - something to work around system limitations of the MAC OS when installing printer.
You can name your printer as you want (4).
2. Select driver for your printer:
It should be "HP DesignJet 450C - Guteprint"
3. Click Add in Add Printer dialog
Now, try to repeat your steps in printing from AutoCAD and use name of the printer, that you just install (4 on first screenshot).
Thanks for the detailed response/instructions. Added printer exactly as you described...still prints with same poor results. I noticed your printer driver for the DesignJet450 was v5.2.3, mine was v5.1.3 (as all of my Gutenprint drivers are). I am using Mac OS X 10.5.8, not Snow Leopard, for what it's worth.
Hope I can resolve this soon as I have only 6 days left on my trial and I was seriously considering making the investment in the program. so far its been a real deal killer.