Print refers to the number of fully opened sheets of paper needed to print a book. The fully opened paper is divided into type A (format 850× 1 168) and type B (format 787× 1092), and the format refers to the size of the paper in millimeters.
Paper is the unit of measurement for printing paper. The whole paper has two printing faces, namely the front and the back. Specify that one printing surface of the whole paper is a printed page. After a whole piece of paper is printed on both sides, there are two.