Cleat sewing is not a new form of sewing. It has been around for decades and has proved its worth to the bookbinding industry. After the glue or the fold on the back of a magazine has been removed, the sewing process begins by making a series of angled saw cuts three millimeters deep.
Each pair of cuts is called a cleat (hence the name). Each cleat is then sewn individually by a needle working from side to side in the form of a figure 8 between each saw cut of the cleat. The thread passes through glue as it is sewing which helps to hold the pages in place until the main gluing process, which happens after the book is completely sewn. The back of the book (called the spine) is then completely glued, and the book is placed on its front edge so that gravity takes the glue to the bottom of the saw cuts, sealing in the thread. The benefit of this style of sewing is that it only takes in three millimeters of the spine & is flexible, which allows the book to open reasonably flat, while still providing a very strong spine.
Omcoa sewing is an exceptionally strong method of over-sewing a book. It works by placing three millimeters of pages into the machine, then a series of holes is punched into them allowing the needles to go through the holesforming loops, which, when pulled tight, lock in the thread and the pages. Then another three millimeters of pages are placed on the top & the process begins again until the book is complete.
This style of sewing is mainly for magazines and newspapers with minimal margin allowance. Each section is manually sewn through the centre of the fold and around binding tape. The length of the book determines the number of tapes used. The benefit of this style allows the book to open completely flat and all the print even if it crosses over the middle of the section is still readable. This is a labour intensive process therefore attracts a premium.
This is a strong way of binding single pages together. It is suitable for journals, newspapers, in fact all kinds of binding. The pages are fanned out over a glue roller then reversed and fanned out the opposite way. This gives a minimum amount of glue between each page and therefore allows the book to open flat. This leaves the book with maximum margins so is ideal for books with printing close to the spine. As it isn't as labour intensive as hand sewing it doesn't attract the same premium.