A3 Copying Paper

Copier paper is the plainest thing in a stationery shop and the one most often bought wrong. What matters is not the name on the wrapper but the weight and the surface: a sheet that is too light jams a duplex printer and shows the print from the other side, and one that is too rough leaves toner sitting on the surface instead of fused into it.

A3 is exactly twice the area of A4, which makes it the size for spreadsheets, plans, posters, layout proofs and anything meant to be folded down to A4 afterwards. If you print A3 only occasionally, buy the smaller pack: paper takes moisture from the air, and a part-used ream left open in a humid room curls at the edges and then starts feeding crooked.

• A3 — twice the area of A4
• For plans, spreadsheets, posters and layout proofs
• Keep the ream wrapped until you need it
• A part-used pack left open will curl and misfeed