User`s guide

margins
Syntax: margins top left
Function Returns the two margin adjustment parameters set by
setmargins.
Default 0, 0
Errors stackoverflow
setmargins†
Syntax: top left setmargins
Function Adjusts the printer’s margins by changing the
alignment of the imageable area on the page. The top
and left operands are integers that specify distances in
device space (the unit size is one device pixel or 1/300
inch). A positive top widens the top margin and a
negative top narrows it relative to the standard margin
width. (The top of the page is the edge that emerges first
from the printer.) Similarly, a positive left widens the
left margin and a negative left narrows it.
setmargins is intended only for use at installation time
to correct any physical alignment errors that may exist;
it has nothing to do with setting the dimensions of the
imageable area. The printer hardware imposes margins
that cause the image to be clipped if it is moved too
close to the edge of the paper; unfortunately, the
hardware-imposed margins are not symmetrical about
the center of the paper.
Errors invalidaccess, rangecheck, stackunderflow, typecheck
Chapter 10
PostScript: Operator Dictionary 10-29