How can I save and later return to an x,y position in postscript?

Regarding the response by abeddie - "currentpoint /y exch def /x exch def":

Saving the values of the current x and y positions and then later using them to perform a x y moveto works fine as long as the current transformation matrix is the same as when the x and y values were stored. If there has been a scaling operation, or a rotate operation, or some other transform, then the stored x and y values are just numeric values that will position according to the now current transformation matrix, not the past position that you want to return to.

I would recommend using gsave and grestore which will return the graphics state, including the transformation matrix, to the corresponding saved state.

What you will need to keep in mind is that operations that affect the graphics state, performed after the gsave, will be lost when you use grestore (ie. the introduction of new fonts and font sizes).