الوصف

Printing paper is a type of paper used to print documents as well as to copy them. The specifications are A0, A1, A2, B1, B2, A4, A5. etc. A4 paper, which is commonly used, is widely used for examination papers.
Classification by length and width
Paper specifications refer to the paper is made, after trimming and cutting the edges, cut to a certain size. In the past, the size of the paper was expressed in terms of how many "openings" (e.g. 8 or *6 openings, etc.). China's adoption of international standards, the provisions of A0, A1, A2, B1, B2, A4, A5. and other marks to indicate the width of the paper specifications. Standard provisions of the width of the paper (expressed in X) and length (expressed in Y) of the proportional relationship between X: Y = 1: n .
According to the basic area of the paper width, the width specifications into A series, B series and C series, width specifications for A0 width size of **1mm × ***9mm, width area of 1 square meters; B0 width size of ***0mm × ***4mm, width area of 2 ^ 0.5 square meters; C0 width size of **7mm × ***9mm, width area of 2 ^0.*5 square metres; the width specifications of copy paper are only used for the A series and B series. If the A0 paper along the length of the way to open into two equal parts, it becomes A1 specifications, the A1 paper along the length of the direction of open, it becomes A2 specifications, so open to A8 specifications; B8 paper also according to this method to open to B8 specifications. A0 ~ A8 and B0 ~ B8 width size is listed in the table below. Among them, A3, A4, A5, A6 and B4, B5, B6 and other 7 kinds of width specifications are the common specifications of copy paper.
For example, "A4" paper is the basic size A paper folded four times, so the area of an A4 paper is one fourth of the area of the basic paper, i.e. 1/*6. and so on.