This is a simplified (perhaps over-simplified) description of what goes on when we manufacture your book. I felt this overview was necessary if you want to understand what each deparment is doing as you surf through our Book Factory Tour. - by Rich Savitski
When printing your book, Thomson-Shore uses a process called Offset Photolithography. The basic steps will be outlined below, then the Book Factory Tour will show how each department contributes to this process.
Note: This description shows how to print a book the "traditional" way. There is new technology called Electronic Prepress that allows you to bypass the camera and layout stages if you supply your book to us on a computer disk. For more inf ormation, see the Electronic Prepress department in the Book Factory Tour.
1: Begin with "camera ready art". This basically consists of black letters on a white background. This is created using a typesetter or a desktop computer/printer.
2: We take this art and photograph it to make a negative. This negative is usually the same size as the original art. The white areas on the original art are now solid black, and black areas on the original art are now CLEAR.
3: These loose negatives (one negative per text page) are stripped up (or taped) onto an opaque carrier sheet, usually 16 text negatives per sheet. A window is then cut in the sheet for each negative to allow light to travel through the clear areas of the negative.
This carrier sheet will produce one side of a press sheet. The negatives are stripped up in the proper order and orientation so that when the press sheet is printed and folded, the pages will be in the proper order. This order is called the imposition. The carrier sheet with the negatives stripped in is called a flat.
For every press sheet, there is a front and a back side, so there is also a corresponding front flat and a back flat. If each flat has 16 pages on it (as in the above example), then each press sheet, front and back, will contain 32 full pages.
4: The flat is set over a photosensitive, thin, metal plate using register pins for accurate placement. When light is shown over the flat/plate combination, the negatives only allow light to travel through the clear areas. This exposes only certain areas of the plate to light. After a specific exposure time, the plate is developed so it is no longer sensitive to light. The area that was exposed to light can now be seen on the plate. This area corresponds to the black type on the original camera ready art.
5: This plate is mounted on a cylinder on one of our printing presses. Using a special process involving water and ink, the ink is attracted to the exposed area on the plate. In a rolling motion, the plate passes the inked image over to a rubber blanket, and this blanket presses the ink onto the sheet of paper.
6: These sheets are allowed to dry and then go to the folders. The folders fold each sheet 4 times.
This makes what we call a signature; 1-32 page section of the book. A 96 page book will have 3 signatures.
7: Our binding equipment groups these signatures together into an F&G (or fold&gather).
Here is where the binding changes based on if it is Perfect bound or Case bound:
For perfect bound books, the binding side (or the spine) is shaved by about 1/8" then glue is applied to the cut area. An oversized cover is then applied to the glued area and wrapped around the F&G. When the glue dries (usually a matter of seconds), the F&G's are sent to the 3-knife. The 3-knife cuts the remaining 3 sides (top, front and bottom) of the book to give it nice, clean edges. The perfect bound book is now complete and ready for boxing.
For case bound books, the F&G's are sent to the sewing machines. We use a stitching process called Smythe sewing to sew the binding edges of the F&G's, together. The binding side is never shaved like in perfect binding. That is why you cannot get the same inside margins for perfect bound books and case bound books. (If you need identical margins in both hard and soft cover books, we can Notch bind your soft cover book - see Notch binding below).
The hard cover cases are made by applying glue to binders boards and wrapping colored cloth around them. The cases are made to exact specifications based on the size and bulk (or thickness) of the F&G's. The cases are usually stamped on the front and the spine with colored foil stamping (usually the title & author).
Endsheets (folded sheets of heaver stock than the text) are glued to the front and back of the sewn F&G's and then the F&G's are trimmed on 3 sides (top, front and bottom). Just like in perfect bound books, this 3 sided trim gives the pages a smooth and clean edge. The front and back endsheets are now glued to the inside of the cases to attach the cases to the trimmed and sewn F&G's. You now have a complete case bound book. If jackets are required, they would have been printed ahead, trimmed, and applied at this time. The books are ready for boxing.
If you require the inside margins of your hard and soft bound books to be the same, we can Notch Bind your book. At the folding stage, we add a special wheel to the folder that puts notches on the binding side of the signatures. When the signatures are gathered into F&G's, the 1/8" does not have to be cut off the spine edge. The notches allow the glue to penetrate to each fold of paper. The binding process continues as if it were a perfect bound book. Currently, we notch bind most of the soft cover books we print.
I hope this gives you a better understanding of the process of manufacturing your book.