Consult your printer’s manual or check any on-printer graphics to learn whether to place paper with the already-printed side up or down. For most printers, the printed side goes up.

Mugi Yamamoto created the Stack, an inkjet printer that eats its way down a stack of paper, swallowing each piece underneath, printing it, and depositing it on top of the machine. Image: Mugi Yamamoto ...

I have a stack of scrap paper that I sometimes print on. I think I heard at one time that it was bad to print on the same sheet of paper twice, with a laser printer. Is it? I have an HP LaserJet ...