Open refers to the area of single-sided paper after books and periodicals are formed, which is equivalent to one-third of the single-sided area of the whole paper. If it is thirty-two, the single-sided area of the book is equivalent to one thirtieth of the whole paper; Sixteen quarts means that its single-sided area is equivalent to one sixteenth of the total paper area. The whole paper is folded in half once, and the width becomes half of the whole paper, which is called folio. If you fold it in half again, the width will become a quarter of the whole piece, which is called quarto. And so on. There are also unfolded opening modes, such as 1 1 open, 14 open, etc. But some paper is always wasted, so it is only used for special needs.
In China, the flat paper used for printing is mostly 787× 1092mm, and the plate-making, printing and binding machines are also designed with this paper. However, some countries that produce printing machinery in the world have already eliminated this small format. Therefore, China has decided to gradually take the large-size printed plain paper of 880× 1230mm as the standard in the future. When cutting into volumes, the quantity determination method is the same as the original one. However, because the whole paper is large, it is also large when it is cut into the same size, so it is customary to call the latter a big mouth and the former a small mouth. For example, there are two kinds of books and periodicals with 32 pages: large books with 32 pages and small books with 32 pages.
Hexadecimal: general A4 printing paper, specification: 2 10 mm× 297 mm.
Thirty-two quarts: half the size of A4 paper, that is, 210mm×148.5mm..