Originally Posted by
linsj
I've been doing this since my first printer that wasn't dot-matrix with holes on the sides. I actively keep every sheet with a blank side. My current printer has two trays; one is stocked with second-sided paper for printing whatever doesn't need to be on new paper, which is most of my printing.
Me 2. Since the last millennium.
However, due to humidity levels the second printing is quite curly so one needs to monitor output tray if printing larger jobs.