Double-sided printing is one checkbox when the printer supports it, and one careful flip when it doesn't. The only real trap is the long-edge/short-edge setting - here's what it means.
Quinn Yoo
In any app, Ctrl+P -> find 'Print on both sides' / 'Duplex' in the main dialog or under 'More settings'/'Printer properties'. Choose 'Flip on long edge' for normal documents. If the option exists, your printer has automatic duplex - it prints side one, pulls the page back in, and prints side two.
If you never see the option, first check it isn't hiding in the printer's own driver panel (Printer properties -> Finishing/Layout tab), and confirm the full driver is installed - printers set up with generic drivers sometimes lose their duplex option. Still absent? The printer likely has no duplexer; skip to the manual method below.
Mac: Cmd+P, and in the expanded dialog (click 'Show Details' if collapsed) find the 'Two-Sided' checkbox near the top or under the Layout section - same long-edge default applies. The setting sticks per printer in most apps via presets: set it once, save as a preset named 'Double-sided', and it's two clicks forever after.
Phones print double-sided too when the printer supports it: iPhone - share sheet -> Print -> tap the printer options and toggle Double-sided; Android - print dialog -> expand the options chevron -> Duplex/Two-sided. If the toggle is missing on mobile but present on desktop, the printer's mobile path (AirPrint/Mopria) may not expose it - print from a computer for duplex jobs.
'Flip on long edge' means the sheet turns like a book page - correct for portrait documents, which is to say almost everything: reports, essays, contracts. 'Flip on short edge' turns it like a notepad page over the top - correct for landscape documents and anything you'll bind along the top edge.
Pick wrong and every second page prints upside-down - the most common duplex complaint there is. The memory aid: match the flip edge to the edge you'd bind. Portrait/book -> long edge. Landscape/flip-chart -> short edge. When in doubt, print pages 1-2 of the document as a test before committing the whole report.
Every print dialog offers manual duplex: choose 'Print odd pages only' (Windows: Pages -> Odd pages; Mac: Paper Handling -> Odd only), take the printed stack, reinsert it, then print even pages. Some drivers even have a 'Print on both sides (manually)' mode that pauses and prompts you mid-job.
The whole trick is knowing your printer's flip: does paper come out face-up or face-down, and which end leads when it goes back in? Burn one test sheet to learn it - mark an X on the front-top of a page, print one page, then experiment with reinsertion until a second print lands on the back, right way up. Write the recipe ('printed side up, top edge in') on a sticky note on the tray; your future self will thank you. And re-feed the stack in small batches - manual duplex is where paper jams go to party.
To stop choosing every time: Windows - Settings -> Bluetooth & devices -> Printers -> your printer -> Printing preferences -> set duplex as default; Mac - print once with your saved 'Double-sided' preset and most apps remember the last-used preset. Office printers often default to duplex already; home printers almost never do until you set it.
Worth keeping single-sided: anything to be signed and scanned (double-sided contracts scan messily), labels and card stock (most duplexers can't take heavy media - check the duplex path's paper weight limit, often lower than the main tray's), and photos. For everything else, duplex halves your paper use without a visible downside - the rare 'ghosting' of dark pages through thin paper is fixed by 80gsm-plus paper or the draft-quality toggle.
If 'Print on both sides' appears in the print dialog with the correct driver installed, it can. Or check the model's spec sheet for 'automatic duplex'. Compact and budget printers often skip the duplexer; their dialogs offer only the manual odd/even method.
The flip-edge setting is wrong for your page orientation: portrait documents need 'long edge', landscape needs 'short edge'. Change that one dropdown and reprint - it's almost never anything else.
It halves paper use, which for a home office printing a few reams a year is real money and shelf space. Note it doesn't save ink - same pages, same toner - and auto-duplex prints slightly slower because of the re-feed pass.
Yes - booklet mode (in Adobe Reader's print dialog, or many printer drivers) prints two half-size pages per side, ordered so the stack folds into a booklet. It's duplex plus imposition: choose 'Booklet', short-edge binding, and fold the output down the middle.
