Please tell me some common sense and basic types of paper classification.

Paper size classification and common sense of use

The format size stipulated by the state is an international standard series, which has been incorporated into the national industry standard GB/T 1999 and implemented nationwide. At present, the format size of books and periodicals is mainly series A specifications, as follows: A4 (16k) 297mm× 210mm; a5(32k)2 10mm× 148mm； There are three models of A6 (64k)144mm×105mm, of which A3(8k) has not been determined, but 420mm×297mm is widely used. A2 (2k) 420mm× 594mm.

The concept of open number and folio

Usually, a flat base paper cut according to national standards is called full open paper. Under the premise of not wasting paper and facilitating printing and binding production, cut the fully opened paper into several small pieces with the same area, which is called how many sheets; Binding them into a book is called how many folio.

For the text of a book, the meaning of the folio number is the same as that of the folio number, but for the folio number of the cover and the insert, the meaning is different because of the different areas. Usually, the size of a single-page publication is called folio, such as newspapers and wall charts, which are divided into full page, folio, quarto and octavo.

Because there are several different series of paper formats at home and abroad, although they are all cut into the same size, but the specifications are different. In actual production, full paper with a width of 787× 1092(mm) or 3 1×43 inches is usually called orthogonal paper. Full paper with a width of 889× 1 194(mm) or 35×47 inches is called heavy paper. Because the format of 787× 1092(mm) paper is defined by China itself, which is inconsistent with international standards and is a non-standard format that needs to be phased out.

In order to make books and periodicals easy to fold into volumes, most printing papers are cut in multiples of 2.

Uncut paper is called whole paper, and the format of half-cut whole paper is called folio or half-open; The width of the folded paper is called the fourth power; The width of the folded four-fold paper is called 20% off.

According to the national standard 1965, the format of books and periodicals is divided into three groups: A, B and C. The original paper in group A is 880mm× 1230mm, B is 787mm× 1092mm and C is 695mm× 960mm. In 1982, GB 788-87 emphasizes the adoption of international standards, which is now being popularized. The new standard retains the A series in the old standard, adopts the B series in the international standard, and cancels the folio of B and C in the original standard. Its purpose is to promote foreign trade and international exchanges. A4, B5, etc. That is, when we usually copy it, it is an international standard.

The format size stipulated by the state is an international standard series, which has been incorporated into the national industry standard GB/T 1999 and implemented nationwide. At present, the format size of books and periodicals is mainly series A specifications, as follows: A4 (16k) 297mm× 210mm.

I. Paper format specifications

The specification of paper refers to that after the paper is made, it is trimmed and cut into a certain size. In the past, the paper size was expressed by the number of "open" (such as 8 open or 16 open, etc.). ). Now I adopt the international standard, and stipulate that the format specifications of paper are indicated by A0, A 1, A2, B 1, B2, etc ... The standard stipulates that the proportional relationship between the width (indicated by X) and the length (indicated by Y) of paper is X: Y = 1:.

According to the basic area of paper format, the format specifications are divided into A series, B series and C series. A0 has a folio size of 841mm×1189mm and a folio area of 1m2. B0 has a width of1000 mm×1414 mm and a width area of 2.5m 2:C0 has a width of 9 17mm× 1279mm and a width area of 2.25m2. Only A series and B series are used in the format specification of copy paper. If A0 paper is split in two along the length direction, it becomes A 1 specification; if a piece of paper is split in two along the length direction, it becomes A2 specification, and then it is split into A8 specification. B8 paper is also split into B8 standard in this way. The format sizes of A0 ~ A8 and B0 ~ B8 are shown in the following table. Among them, A3, A4, A5, A6, B4, B5 and B6 are common specifications of copy paper.

Paper format, specifications and dimensions

measure

Width (mm)

Length (mm)

measure

Width (mm)

Length (mm)

A0

A 1

Aortic second sound

A3

A4 size

A5

A6

A7

A8

84 1

594

420

297

2 10

148

105

74

Fifty two

1 189

84 1

594

420

297

2 10

148

105

74

B0

B 1

B2

B3

B4

B5

B6

B7

B8

1000

707

500

353

250

176

125

88

62

14 14

1000

707

500

353

250

176

125

88

If the letter R (or S) is added before the letter of the paper specification mark, it means that the paper is not trimmed and will be reduced to the standard size after cutting. For example, RA4 (or SA4) indicates that the size of uncut paper is 240mm×330mm, and the size after cutting is 2 10 mm× 297 mm.

If the magnification or the reduction magnification, the format and specifications of the copy paper used have a corresponding relationship, as shown in the following figure, which can be used as a reference for selecting the format and specifications of the copy paper when making variable magnification copies; For example, the original in A3 format is enlarged 1: 1.22, and the copy paper should adopt B3 format specification; Zoom in and out 1: 0.8, copy paper shall adopt B4 specification, zoom in and out 1: 0.7, and copy paper shall adopt A4 specification. The specifications of A5, B5 and B6 in the table are rarely used.

2. Selection of copy paper

1. Paper thickness

The thickness of paper is usually expressed by the weight per square meter (grams), and the thickness specification of paper for electrostatic copier is 64 ~ 80 grams per square meter.

2. Paper density

The density of paper refers to the density and thickness of paper fibers. If the fiber of the paper is too thin and too thick (that is, the density difference), the resolution of the copied image is poor, and it is also easy to produce paper wool and paper scraps, which will ruin the copier and make the copy produce bottom ash, so it is appropriate to choose high-density copy paper.

3. Stiffness of paper

Stiffness of paper refers to the firmness of paper texture. If the stiffness is poor, it is easy to encounter a little resistance in the paper feed channel, and the paper will wrinkle or even jam, so choose copy paper with good stiffness.

4. Surface brightness of paper

The surface brightness of paper refers to the brightness of paper surface. The color of the paper should be white, not dark, and the brightness should not be too high, which is not conducive to image fixing.

5. Drying of paper

If the copy paper has low dryness and high water content, it will reduce the insulation performance of the paper, make the copied image (or handwriting) fade, make the bottom ash big, and easily cause paper jam. So choose copy paper with high dryness. On the other hand, paper should be kept in a dry and ventilated place.