PenSize
PenSize Set dimensions of pen for current GrafPort
#include <Quickdraw.h> Quickdraw
void PenSize(wide, high );
short wide ; desired width for the pen
short high ; desired height for the pen
PenSize selects the height and width, in pixels, of the graphics pen for the
current GrafPort. The initial pen size is (1,1).
wide and . . .
high are the desired width and height of the pen. A setting of (0,0) - or
setting either parameter less than 0 - makes the pen in visible
Returns: none

Notes: The wide and high values are stored in pnSize field of the current
GrafPort structure, except that if either value is less than 0, then both
parts of pnSize are set to 0, making the pen in visible.
You can also set the pen size and other pen-related parameters via the
SetPenState function. You can may obtain the size of the pen by accessing
the pnSize field of the current GrafPort; e.g.:
short width, height;
width = thePort -> pnSize.h;
height = thePort -> pnSize.v;
You can obtain this and related information via GetPenState.