Who knew printing had a language all of its own?

This week’s word is the rather grand sounding "royal octavo" (yes, we know it’s technically two words). As anyone who’s ever looked at a bookshelf knows, books come in many different shapes and sizes. But you may not know that each of these sizes has its own official name - and has had for a very long time. The names we use now for book formats are based on the idea that the leaves of a book are made by printing an even number of pages on a large sheet of paper, then folding over the paper a certain number of times. If you printed eight pages of text on a sheet, the resulting book format is an octavo. But of course there were different sizes of paper sheets, so there had to be different types of octavo. So traditionally royal octavo was used to describe a page one-eighth the size of a royal sheet, medium octavo a page one-eighth the size of a medium sheet, and crown octavo a page one-eighth the size of a crown sheet.

These days, however, royal octavo is generally just used to describe a book whose pages measure 10" by 6¼" (253 mm x 158 mm). Lots of our books appear in this format - as well as the even more exotic sounding demy octavo (8¾" by 5⅝", or 221 mm x 142 mm). Who knew printing had a language all of its own?