SynapseDirect

I'm adding this to my templates

color (gray)
newpath at 0x530 line 22x530
color (black)

This prints a small line to indicate where the paper can be folded so that the address appears optimally in my window envelopes.

You may have to play around with this depending upon how close to the edge your printer can print.  For letter paper it's 

color (gray)
newpath at 0x480 line 22x480
color (black)