This process uses wires that pass through the centre of the publication from the front page to the back where they are closed. This binding process does not allow the publication to be opened flat, as the wires constrict the opening of pages. After printing pages are formed into sections which are collected together with stitches to hold the signatures together and then sewed again through the back to keep the signatures in place. Mechanical binding Mechanical binding, using coils, spirals or loops, requires that the cover and pages be punched with holes near the binding edge, so that metal or plastic wires or bands can be woven through the holes. This method allows the publication to be opened flat, and allows more of the image area of a page to be used since the binding does not require wide inside margins.
Pages are hole-punched and can be rearranged in the folder, or added to at any time.
Perfect binding Perfect binding is a process used to replace sewing for books and other lengthy documents. Pages are glued together and a cover applied to hide the glue. This method is less expensive and faster than sewing, and is considered to be of higher quality than any other form of binding. Margins Margins used on a page will usually not be equal in size. For example, a book will have an inside margin that is wide enough for the binding, and perhaps a wider outside margin to balance the text on the pages.