Book Sizes Redux

You may remember (and when I say “you” I’m talking to the single lonely person that reads this blog. Hi!) that a few weeks ago I did a quick thing on book sizes:

It was intended address the endlessly repeated email “What does 8vo (etc.) mean in your book description?”, it was intended to address this question in a quick, flippant easily digestible way. I’m big on quick and flippant…if you look up “flippant” and “superficial” on wikipedia, that’s me, I’m just under the cast of Jersey Shore.

As is supposed to happen (really, this is what blogs are for), Mr. K. left a comment with a tremendously useful addition to the subject which I shall reproduce here. Before we go any further I would like to stress that Mr. K. is totally and completely correct, not to mention articulate and anybody needing further elucidation could do no better than to check this out:


“Dear Bibliodeviant,

No, no, no.
Octavo; quarto; folio, et cetera, indicate how the sheets were folded, before inclusion as gatherings in volumes; by themselves these terms are not indicative of size. There are larger and smaller quarto’s; and larger and smaller octavo’s.

Book size is described by a two part term; for example, demy octavo; demy quarto; imperial octavo; and post octavo.

The first element of the two part term describes the size of the sheet that was used in the printing process. In England, foolscap was amongst the smallest sheets used, and imperial was amongst the largest. Demy was a mid-sized sheet. To complicate matters, there were slight variations in the sizes of the sheets, there was no clear standard – there were large demy sheets, and small demy sheets, for example.

Once the sheets that were used were folded, depending on folding method, – in folio, octavo – do we arive at book size. A foolscap octavo is far smaller than an imperial octavo: because the foolscap sheet is far smaller than an imperial sheet, and the sheets of both had been folded in the same manner, octavo.

A foolscap folio is smaller than an imperial quarto. An imperial octavo is only marginally smaller than a foolscap folio. A demy octavo is only a little smaller than a foolscap quarto.

When reading a book dealer’s description, terms such as quarto,and octavo, should only ever tell us how the gatherings had been folded; not how large the book is. It is difficult and time consuming to determine exactly which sheet had been used in the printing process, so book dealers of old had simplified matters by describing copies as large or small octavo’s; and large or small quarto’s.

The size of some editions are famed, and the correct description remains in use. Dickens’s demy octavo’s are amongst the most recognisable of book sizes, for example. In the literature of the day, titles were advertised, as to their size, and when these are still known, they are often included in the descriptions of book dealer’s stock.

When the folding of sheets had become superseded by other technologies during the twentieth century, attempts were made to standardise the two term descriptions as sizes in inches; and these vary from one source to the next, are still wrapped in confusion, and are without any real use.

Kind regards, K.”


Obviously this is excellent information. The reason it wasn’t in the original blog post is that

a) it doesn’t answer the email question because the correct and most immediately useful answer is “It’s about this big!” (wait with baited breath for my upcoming post on “Why we make it difficult for you to buy books! Usage versus Tradition.”)


b) in the shop I would hold up a selection of books of various sizes (without the aid of the bald chap, who is in fact my younger brother being a stunt bookseller for the morning) and then do a shtick with a large sheet of paper folding it in a variety of ways like a demented children’s TV presenter until the interested parties understood or, more likely, weren’t interested any more. In future I may actually do this on a video, so that more of you can be not interested and also so that you can be treated to the awfulness of actually knowing what I look like. Again with the quick and flippant…

So many thanks Mr. K. both for providing very useful information, and also for actually reading the blog.


About bibliodeviant

This is the journal of Jonathan Kearns Rare Books & Curiosities, and all who sail in her. Information, updates, rantings, musings and pretty pictures related (loosely I would imagine) to the world of rare and antiquarian books will be brought to you by a number of different personalities, some of whom cohabit in the same person's head. We welcome queries, comments and contributions of virtually any description, and in return we will attempt to rein in our multitudinous personality disorders and deliver wonders and joys beyond compare. At least that's the plan. View all posts by bibliodeviant

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