Let's say you have a drawing with a title block sized 841x594 that is A1. You want to print it to PDF with correct rotation. You don't want it 594x841. You also want the offset to be correct and no white margins.
In this example I use Adobe Acrobat 8 Professional.
This is what you get when you select the A1 paper size. Notice the red rectangle that is not rotated correctly.
What you need to do is the following.
Click on Properties...
This will show the Plotter Configuration Editor.
Select the tab Device and Document Settings.
Find Custom Properties in the tree view.
Click on the button Custom Properties.
In the dialog box Adobe PDF Document Properties select the tab Adobe PDF Settings.
You will see Adobe PDF Page Size. Click on the Add... button.
Either add a new page size or change an existing. A1 cannot be changed since it is not user defined.
I added a A1 landscape page size to have the width 841 and the height 594 in millimeters.
When you after that comes to the dialog box Changes to a Printer Configuration File you can select to save the changes to Adobe PDF.pc3.
Now it looks better.
And the result will be as expected.
On the other hand if you want to use the build in DWG to PDF.pc3 that comes with AutoCAD 2007 and AutoCAD 2008 you will not get the result you expect.
First I had to Modify the ISO A1 (841.00 x 594.00 MM) paper size and set the margins to 0.
The preview looks great.
But the resulting PDF will not be located correctly. It is offset up to the right and I have not found a way to solve this. PLOTOFFSET 1 or 0 does not affect the result.
When I tried the same with the freeware PrimoPDF I had no problem to get the expected result.
The same applies to other paper sizes than A1.