According to national standards, the map size is:
A3 (420mm x 297mm)
A4 (297mm x 2 10/0mm)
A5 (148mm x 2 10/0mm)
B3 (353mm x 500mm)
B4 (250mm x 353mm)
B5 (176mm x 250mm).
According to the size, folio is usually divided into three types:
Large format, medium format and small format. For 787× 1092 paper, 12 format is large format, 16 ~ 36 format is medium format, and 40 format is small format, but books with mainly characters are generally medium format. Folio shapes are rectangles with different proportions except 6 quarts, 12 quarts, 20 quarts, 24 quarts and 40 quarts, which are suitable for books with different properties and uses.
In the past, the size of paper was expressed by the number of "open" (for example, 8 open or 16 open, etc. ). At present, China adopts international standards, which stipulate that the format and specifications of paper should be expressed by A0, A 1, A2, B 1, B2 and other marks. According to the standard, the proportional relationship between the width (represented by X) and the length (represented by Y) of paper is X: Y =1:N. ..