soft cover books
Soft cover books are any books that do not have a book board on the cover. They come in a variety of bindings, including perfect bound, notch bound (a version of perfect), PUR, Smythe sewn and Wire "O" - in a variety of types from regular to semi-concealed to fully concealed.
Note: Soft cover books are cheaper to produce than hard cover books, but with automation this difference is usually less than a dollar a book. However, a soft cover usually sells for many dollars less than a hard cover; thus the profit margin for hard covers is much better. However, soft covers often sell more copies because they are less expensive. There are pluses and minuses on both sides. It pays to know your target audience...
Soft cover cut flush
Most soft cover books are perfect bound and are printed just the same as hard covers, on large press sheets, collated, but not sewn. Instead the back of the collated book is shaved off roughly, glue applied and under heat and pressure it is pressed into the cover and the book block with the cover in place is trimmed on three sides in a large trimming machine. Heat and pressure ensure that the pages will not fall out of the book. Some printers prefer to still use sewn binding because it allows the book to open wider.
Notch binding is a version of perfect binding. The main difference is that small notches are clipped at right angles to the spine to allow more glue to penetrate into the pages.
Saddle stitched books have a soft cover but they are not cut at the spine, they are collated and then opened and placed on a stitching machine that stitches the pages through the cover at the spine, usually three metal stitches. This is how calendars are made, as well as coloring books. There is a limit to how many pages can be saddle-stitched but this number varies between printers and depends on the number of pages and the thickness of the paper.
Smythe Sewn: Usually most US printers use perfect or PUR binding for soft covers cut flush, but in Asia you can frequently get smythe sewn with soft covers cut flush if you request it.
Soft cover with flaps
A soft cover with flaps usually has a Smythe Sewn binding. The book block is glued, and cut at the outside edge opposite the spine. The cover is prepared (folded at flaps and spine) and then glued to the book block. The top and bottom of cover and book block are then trimmed in a large trimming machine. This is at least two extra steps and so a flapped soft cover costs more than a regular cut-flush soft cover. More paper in the cover is also a factor in price.
Recommendations: The cover of a soft cover with flaps can be C1S (coated one side) or C2S (coated two sides). We prefer C2S glossy cover stock because part of the cover will be folded back, and C1S is quite a bit stiffer than C2S. The stiffer board is not necessary when you have flaps. We also prefer 250 gsm cover stock (10 pt) instead of 300 gsm (12 pt) because it is less likely to form a vertical line across the front cover where the flap stops because of the weight pressure in the shipping cartons - the thinner stock will make less of an impression. Finally we prefer glossy film lamination rather than matt film lamination for books with flaps because the flap requires more manipulation in manufacturing, and matt film lamination accentuates any small machine scratching.
Other binding for soft covers
Wire "O" binding is like comb binding, it opens up and is clamped through die-cut or drilled holes in the text block. Sometimes the binding can get squashed in shipping, and that can result in pages coming out.
Wire "O" can be regular, that is, just going through the cover, semi-concealed, or concealed. Below is concealed wire "O".
Recommendations: For Bolton Associates we find regular wire "O" bound books difficult because of the fact that they do not shrinkwrap well, and the wire can scratch the covers of the books stacked on top of each other in their cartons. For that reason the fully concealed wire "O" is recommended by us. That fully concealed binding comes in a hard cover format as well.