Papermaking

The eleventh entry is la main du papier, and it is the one term on this page an English reader can misread without ever suspecting it. The rest of the list announces itself as technical. This one produces a phrase that looks like ordinary English: « the main » of a thing is its principal part, so la main du papier reads as the chief property of the sheet, a heading rather than a measurement — and whatever sentence follows will still make sense, which is why nobody stops to check. The two words share their spelling and nothing else. French la main is the hand: serrer la main, fait main, donner un coup de main, haut la main. At the machine that hand has become a measurement, the bulk of the sheet, thickness weighed against weight, which is what a printer judges by lifting a ream and what makes one book fatter than another of the same length. Say « bulk » and never « main »; the adjective is principal in French.