Ditial Prepress--Beta Watch!

The beta: At Offset Paperback, a full signature consists of two films with 32 pages on each. Two films make the front and two films make the back of the plate, which makes 128 pages. The geometries of the two front films are almost, but not totally, identical, because the shingling is different. The web is slit into four ribbons, which are cut across and stacked on top of each other before being folded, four sheets at a time. The geometry of the back film is a mirrored image of the corresponding front and page numbers are either one up, or one down.