The following "boxing" can occur when the page size does not match the paper size that the printer is configured to be printing on:

Under File > Page Setup, make sure that Horizontal and Vertical are both at 1 and 1 and that Choose Size Unavailable in Printer Setup is set to One Printer Page. Use Printer Setup to alter your paper size. DO NOT manually change Width and Height in Page Setup or your print will not be scaled properly.

A common issue on Macs is that the margins or paper size will not set properly. The Mac OS is easier to troubleshoot as all of the print setup options are the same for every machine, unlike windows where each printer will have its own variation of the printer setup.
Go to File > Page Setup

Users will often assume setting the page size to "Arch D" or "ASME C" will make their printer choose that paper size, this is incorrect. The setting here is telling Vectorworks the Page Size, it is not instructing the printer to use a specific kind of paper. The "Horizontal" and "Vertical" boxes on the top left corner will always read 1 and 1 when configured properly.

