Paper weights, and the table nobody agrees on
Two paper systems, one of them measuring a quantity that changes depending on what the paper is for. Here is the conversion table, and the honest reason it can never be exact for every sheet on it.
Tag: #workflow
Imposition: why page 1 sits beside page 8
Fold a sheet three times and the page order stops being obvious — page one ends up beside page eight, upside down. Printers solved this before 1500, and every book you own is still assembled by their answer.