Smyth sewing (note no “e”) is now quite rare, but when I started working in the industry probably about 90% of books were bound this way. Now only de luxe books and books from smaller university presses are being sewn.
Sewing is done after the signatures have been gathered (and if it’s a hardback, after the endpapers have been tipped to the 1st and last sigs). The operator picks up each sig in sequence and places it over a saddle-like structure with holes in the middle to allow a series of needles to come up and penetrate the back fold of the sig. Immediately the next sig is placed over the saddle and sewed to the previous one. This continues until you have a complete book block joined by threads. Indeed it continues immediately after too, as the next book is lightly joined to the previous one in a continuous process. In hand binding sewing is done with a needle and thread. Smyth machines automate this process, but sewing is still a labor-intensive process. Because of this, it became an early target for those attempting to bring greater efficiencies into the bindery. One by one the big book manufacturers closed their sewing departments in an attempt to cut cost out of the process to respond to the demands of their customers.
Smyth sewing has the reputation of being the strongest form of binding, but this is a bit of a sentimental myth, I believe. Sewing will eventually loosen up, but it does tend to stay good and tight for a long time. It’s not that it is un-strong, it’s just a matter of how you define strength. The strength of a chain is its weakest link, and in a sewn book the “weakest link” is the center four pages of the sig, where you can see the threads when you open the book. Page pull and flex testing (they have little machines that do this in a controlled manner) will cause the thread to tear through the paper quite quickly, so that the center four pages come away from the book. Other forms of binding, e.g. notch binding and even perfect binding will out-perform a sewn book in this test. It can be argued that page pull and flex testing doesn’t represent real-life wear and tear on a book. It also test books just off the binding line, and the adhesives are fresh. Obviously the outer leaves of the sewn signature are much stronger than any page in a perfect bound book, and the average strength of all the pages must be much higher in a sewn book. It’s just that in the perfect bound book no pair of pages will be weaker than the weakest foursome in the sewn book: but no leaf in the perfect bound book will be stronger than any other.
Anyway Smyth sewing isn’t the strongest way to bind a book, however you measure. I don’t know what really is, but side sewing must have a good claim to that title. Smyth sewing is the way we’d ideally like to see our books bound: we all regret its passing, while eagerly participating in killing it off by demanding ever cheaper prices.
For other styles of binding search “binding styles”.
Jarrolds bindery c. 1960
Making Book 
[…] a lot of planners you see, the UPstudio 2017 edition doesn’t use wire binding—it uses the smyth sewing technique instead. As a lefty, there’s nothing more annoying than trying to find a […]
Your comment is a bit abbreviated! Some of it appears to be missing. I know a lot of things are made tougher for lefties. I dare say lots of planners are still being sewn — I was talking mainly about trade books I guess, the sorts of books you’d buy in a bookstore. Academic and reference books are still often sewn, and I expect there are other categories apart from planners where this is true.
Thanks for commenting.
[…] See also Bookbinding by hand and Fine binding. For the commercial method of doing this task see Smyth sewing. […]
[…] that you have lots of little piles of sigs, each making up an 11-sig book, they will go into the sewing department where they’ll be joined up into untrimmed book blocks. Case are made from board […]
Hi Richard, I’m glad your blog came up right away when I did a web search on book binding, it answered so many of my questions!
One thing I’ve been scratching my head about for years, now: Why have publishers abandoned sewn bindings for hardcovers? I assume it’s because it’s cheaper to glue them instead, but how much cheaper can it be? At Barnes & Noble, I’ve seen several books with sewn bindings that are clearly of cheap construction–glossy laminated cardboard boards that will chip in the corners in no time. I have a paperback in my hand that has a sewn binding, purchased there in April of this year for $8 (now available for $5). This mystifies me.
Publishers have abandoned sewn binding because it is more expensive. Not a lot more expensive, but all publishers are keen always to improve their margins, and a few cents here or there add up to margin. (It also takes a little more time which may also factor in.) Like any change this started in a herky-jerky way: first a few books were unsewn, and publishers saw no adverse sales implications, so then a few more were. Eventually everyone recognized that not sewing a book won’t actually have any effect on sales. When I started out we used to believe that libraries wouldn’t buy unseen books, so we sewed them all. Turns out this isn’t the case.
Now of course you will still find some sewn books. Not every publisher behaves in exactly the same way, so the corners I cut may be different from the corners you cut. It’s also true that it’s often pretty cheap to sew a book if you manufacture overseas, so the publisher will just go with it. There are also still some university presses and certainly some de luxe publishers who will always sew their books. For instance the Library of America books are all sewn. Dover Books still, I think, sew all or most of their books: maybe that $8 book is one of theirs. The price of a book is dependent primarily of the number of copies printed: economies in the materials and processes used are often used to make it possible to price the book at the desired level with a lower print run.
[…] gatherings (or sections or quires) of most books are sewn at the centre of the fold. [See Smyth sewing.] But thin (and not so thin) books, pamphlets, magazines or part-issues would sometimes be sewn […]
[…] at! These 48 pages are held by two wire staples. I dare say a needle could go through to allow for Smyth sewing, but I expect perfect binding might be problematic. In a paperback book, the perfect bound pages […]