Printing paper refers to a kind of paper used for printing and copying documents, and its specifications are A0, A 1, A2, B 1, B2, A4, A5, etc. The thickness of ordinary printing paper and copy paper is 70 ~ 80g/m2. Paper specifications classified by length and width refer to the fact that after 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.). ). I adopt the international standard, and stipulate that the paper format specifications are represented by A0, A 1, A2, B 1, B2, A4, A5 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 ... 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 half along the length direction, it becomes A 1 specification; If A 1 paper is split along the length direction, it becomes A2 specification, and so on, it becomes 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, seven format specifications such as A3, A4, A5, A6, B4, B5 and B6 are commonly used specifications for copy paper. For example, "A4" paper is a type A basic size paper folded four times, so the area of an A4 paper is a quarter of the area of the basic paper, that is,116. The rest and so on. There is also a kind of K-type paper, which is often called open-type paper. K-type paper can only be used in China. Generally, A-type paper is used. Whether it is type A or type B, its classification is like this. For example, A5 is twice as big as A6, A4 is twice as big as A5, A3 is twice as big as A4, B4 is twice as big as B5, and B3 is twice as big as B4. However, the classification of K type is to divide a large piece of 1K paper into two pieces, a piece of 2K paper into four pieces, 4K paper into half pieces, 8K paper into half pieces, 8K paper into half pieces, and 16K pieces. 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； a6(64k) 144mm× 105mm； a3(8k)420mm×297mm； Note: The size of A3(8k) has not been determined, but it is widely used. A4(2 10*297mm) paper is widely used to print copy paper in the world, but the United States and some countries use abnormal A4 paper: 2 16*279mm, commonly known as American standard and American standard. The corresponding sizes of different types of paper are as follows: 2. Classification by weight or thickness: and classification by paper thickness, such as 60g, 70g, 75g, 80g, 85g, 90g, 100g, 120g, etc. , which means that the weight of paper per square unit area is multiple, because the density of paper is basically the same, the heavier the paper per unit area is. For example, general printer paper is about 40g, all-in-one paper is 50-60g and copier paper is 70-85g. Generally, the printer paper should not be less than 60g, otherwise it is easy to jam. For example, 70g A4 paper means that the weight of the paper is 70g per square meter, not 70g per sheet. The actual weight of an A4 paper with a basis weight of 70g is: 0.2 10×0.297×70=4.3659 References:

(Most offices in southern and coastal areas use 80g paper, while mainland and northern areas mainly use 70g printing paper. Computer printing paper for office automation series stylus printers is classified by size and number of layers, such as 24 1- 1, 24 1-2, which respectively represent 1 and 2 layers of narrow-line printing paper, and of course there are 3 layers and 4 layers. Commonly used wide-line printing paper also includes 38 1- 1, 38 1-2 and so on. For example, 24 1-2 refers to carbonless printing paper (also called pressure sensitive paper, computer printing paper, computer paper, etc. ), can only be printed on a stylus printer. 24 1 stands for: 9.5 inches, that is, the width of paper, also called 80 columns of printing paper (width 9.5 inches * height 1 1 inch), that is, a common font with 80 words in a row (that is, 80 words for short). The main uses of these bills are: delivery/receipt documents, financial statements, ocean air bills of lading, house bills, consumption bills, bank bills, and the main applications are: government departments, enterprises, banks, hospitals, express delivery companies, supermarkets, hotels, KTV, clinics, docks, air transportation, sea transportation, etc. 2 Carbonless copy paper Carbonless copy paper, also called pressure sensitive printing paper, consists of upper paper (CB), middle paper (CFB) and lower paper (CF). It is based on the principle of chemical reaction between the developer of microcapsules and the acidic clay in the developer layer. When printing, press the paper with a printing needle to achieve the color development effect. Common and commonly used color layers are 2 to 6 layers. When buying carbonless printing paper, pay attention to whether the outer packaging of the paper is damaged (if the outer packaging is damaged or deformed, the paper inside may be colored). B: Open the outer package, and check whether there is a certificate of conformity in the package, whether the paper is wrinkled due to moisture, and whether the color development can meet the requirements you want (usually tear off a copy in a normal way and write a few words on it, and then see the color development degree of the last layer) C: Confirm whether the specifications of the printing paper are what you need, so as not to cause unnecessary waste and trouble. Commonly used carbonless printing paper specifications are 80 columns or 132 columns, as well as special specifications (width, length, horizontal and vertical grid, etc. ). The most commonly used is 80 columns, the size is: 9.5 inches X 1 1 inch (with holes on both sides, 22 holes on each side, and the spacing between every two holes is 0.5 inches), which is about equal to 241mm x 279 mm. 80-column paper is usually divided into three specifications: 1: full page (9.5 inch X 1 1 inch). 2: one half (9.5 inches X 1 1/2 inches). 3: one third (9.5 inches X 1 1/3 inches). After unpacking, it should be noted that if it is not used for a long time, it should be put into the original plastic bag to prevent moisture damage. If it is carbon-free copy paper, be careful not to be squeezed by sharp objects or external forces, so as not to cause color development and affect the use. Before using the product, you should confirm the gear of the printer. When multi-layer printing, high-speed printing is not needed as far as possible to ensure the readability of printed handwriting. When saving documents, we should pay attention that each copy should be saved separately. If they must be stored together, avoid squeezing. Avoid light, water, oil, acid and alkali. Carbonless printing paper can be stored for at least 15 years as long as it is in a suitable environment. If there is a paper jam during printing, please check whether the position of the printing paper is appropriate, whether it is aligned with the tractor, and whether the print head has selected a position suitable for the number of paper layers. Bill printer or push printer is most suitable for using multi-link carbonless printing paper products. The design of these printers makes the printing paper not bend in the machine, the printing paper is flat and the printing force is greater. The color of carbonless copy paper is not clear, which may be caused by the reverse loading of printing paper, so it can be reloaded. The reason why the color is unclear may be that the printer pressure is not enough or the needle in the print head is broken. You can increase the printing intensity and check whether there is a broken needle. Color development is a chemical process, which is greatly influenced by environmental temperature. Especially when the temperature is low in winter, the chemical reaction activity is slow, and clear handwriting cannot be seen immediately after printing. This is a normal phenomenon. Main points of purchasing ordinary printing paper When purchasing ordinary printers, you need to refer to the following points: 1. The thickness of paper is usually expressed by the weight per square meter (grams), and the thickness specification of ordinary printing paper and copy paper is 70 ~ 80 grams/square meter. 2. Density of paper The density of paper refers to the density and thickness of paper fibers. If the fiber of paper is too thin and too thick (that is, the density difference), when using an inkjet printer, the reverse side will be soaked, and the printing effect will be poor, which will easily produce paper wool and debris and damage the printer. 3. Stiffness of paper The stiffness of paper refers to the firmness of paper. 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 printing 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. Dryness of the paper If the dryness of the printing paper is low and the water content is high, the insulation performance of the paper will be reduced, which will affect the printing effect, and the bottom ash will be large, which is prone to paper jam. So choose printing paper with high dryness. On the other hand, paper should be kept in a dry and ventilated place. 6. Number of sheets of paper Quantity of printing paper Unit: order. 1 order =500 pieces. Other commonly used newsprint, commonly known as white newspaper, is characterized by softness and porosity, certain institutional strength and good absorption, which can make the ink penetrate and fix in a short time and will not stick dirty when folded. It is used to print newspapers, periodicals and general books on high-speed rotating machines. The basis weight of newsprint is 5 1g/m2, and the width of rolled newsprint is 1572mm, 1562mm, 787mm and 781mm.. The size of the planographic paper is 787mm * 1092mm. Newsprint is suitable for printing and opaque, but its whiteness is low and its surface smoothness is different. When printing pictures, use a thick screen, which is easy to turn yellow and brittle after sunlight, and should not be stored for a long time. Carton board, also known as hemp board, is a relatively strong cardboard used for cartons, which is widely used for shipping books, department stores, radios, televisions, machine parts, food and so on. The quantities are 200g/m2, 3 10/0g/m2, 420g/m2 and 530g/m2. Smooth surface and good mechanical strength. Coated paper, also known as coated paper, is an advanced printing paper which is made by coating a layer of white paint made of calcium carbonate or white clay and adhesive on the base paper, drying and calendering. Because of its fineness and whiteness, high smoothness, good gloss and moderate oil absorption, it is suitable for copper plate printing or offset printing, printing color or monochrome pictorial, pictures, calendars, maps and books, and also packaging and printing paper. It is divided into single-sided coating and double-sided coating, and the two kinds are divided into special number, 1 No.,No.2 and No.3, and the quantitative is 80 g/m2 to 250 g/m2. Coated paper requires high coating strength, no powder loss, and can be suitable for fine screen printing above 60 lines /cm. Offset paper, formerly known as "Dorian paper", is used for books and periodicals by offset press. Suitable for printing monochrome or multicolor book covers, characters, inserts, pictorial, maps, posters, color trademarks and various packaging products. Offset printing paper is divided into special number, 1 number and No.2, and the quantity varies from 70g/m2 to 150g/m2. Pulp has high strength and printability. Offset printing is a relatively advanced printing paper for books and periodicals, which requires high contrast, expansion and contraction ratio and surface strength, and the acidity and alkalinity should be close to neutral or weakly alkaline, so as not to affect the printing paper, and the basis weight is 40 g/m2 to 80 g/m2. Letterpress paper is a kind of paper suitable for letterpress printing of books, stationery and magazines. The basis weights are 52g/m2 and 60g/m2. There are two kinds of paper: roll paper and plain paper. Smoothness 30m, opacity not less than 88%. Letterpress printing paper is a widely used book paper, which is slightly smoother than newsprint and has a longer shelf life, but it is easy to lose hair and powder, so it is not suitable for offset printing books and periodicals. This kind of paper writes easily. Straw cardboard, also known as yellow cardboard or toilet paper, is yellow packaging cardboard. Mainly used for the cover lining of commodity packaging, cartons and books. The ration is 200g/m2 to 860g/m2. Commonly used are No.8 420g, 10 530g, 12 640g. Straw cardboard requires dense and firm quality, smooth paper surface and certain mechanical strength and toughness. White cardboard, also known as Manila paper, is a relatively high-grade white packaging cardboard. Used for printing educational pictures of children and trademarks of stationery, cosmetics and medicines. The ration is 200g/m2 to 400g/m2. Uniform thickness, no hair loss, no powder loss, tough, not easy to break when folding. Binding board is an important material for making bookcases, such as white cardboard and yellow cardboard. , mainly used for making hardcover book covers and envelopes. The hardcover bookcase with cardboard as the skeleton has the advantages of firmness, beauty and long-term preservation. The appearance of calcium paper is similar to that of paper, which is resistant to water immersion, non-hygroscopic, not easy to burn, high in bursting resistance, tear resistance and low in production cost. It is made of 160 degree strong rubbing and calendering, and its thickness is similar to that of cardboard. It can also be made into thick cardboard, which has certain penetration and absorption ability to ink and can print clear pictures and words. It can be used for printing books and cards, valuable securities, labels and color printed matter, and can also be used for making corrugated boxes, transporting food and goods that need moisture-proof and oil-proof. Kraft paper is a tough and waterproof wrapping paper, which is brown and widely used. It is often used to make paper bags, envelopes, record covers, documents and sandpaper. The quantitative range is 40 g/m2 to 120 g/m2, and there are differences between roll paper and plain paper, single side, double side and stripes. The main quality requirements are flexibility and firmness, high bursting resistance, and being able to withstand large tensile force and pressure without cracking. Cellophane, also known as transparent paper, is a kind of advanced packaging and decorative paper as transparent as glass. Used for packaging food, shirts, cigarettes, cosmetics and other commodities. The ration is 30 grams/square meter. In addition to being transparent and colorless, there are many colors such as gold, pink and green. Cellophane is airtight, oily and watery, soft and tough, colorless, transparent and shiny. After sealing, it can be moisture-proof and rust-proof, but it will crack with a slight crack. Because of its great longitudinal strength, it can be used as a paper rope. Waste cellophane cannot be recycled. Sealing paper is an extremely thin single-sided optical writing paper with a basis weight of only 20g/m2. Initially, it was mainly used to seal stamps and insurance letters. Mostly used in cosmetics, fruit and food packaging and cigarette lining. After printing and waxing, it can be used as candy wrapping paper, and can also be used to print documents, subpoenas or multi-page copy paper instead of typing paper and copy paper. Quality requirements are thin and tough, good transparency, high tension and low air permeability. Chinese painting paper is used for writing and painting with a brush, including Yuan Shu paper, Xuan paper and wool paper. Yuanshu paper is made of bamboo, bark, rags, old hemp, straw and other plant fibers through soaking, cooking, natural bleaching and grinding. Hand-made paper on bamboo curtain, pressed and dried on fire wall, the paper is white (or yellowish), uniform and soft, easy to absorb ink and durable. Xuan paper is a kind of painting and calligraphy paper made of sandalwood bark and a small amount of straw pulp. Raw rice paper is suitable for freehand brushwork calligraphy, and cooked rice paper made of it is suitable for meticulous painting, white and flexible, durable and not easy to be eaten by insects. It is famous for its production in Xuancheng, Anhui. Fringed paper is a kind of writing paper with brush made of tender bamboo, and its color is light yellow and white. They are all made of bamboo curtains and used to print ancient books, rubbings, stationery and fans. Glossy paper is a kind of one-sided glossy paper, which is used for writing, office and publicity slogans. It can also be used for pasting paper boxes, packaging goods, printing calendars, stationery and invoices. It has a wide range of uses and is a common household paper. It used to be called office paper or snow lotus paper. There are three special numbers, 1 and 2, and the quantitative range is from 18 g/m2 to 40 g/m2. The quality requires uniform thickness, smooth paper surface, light writing sizing and certain water resistance. Colored glossy paper, also known as slogan paper, is mainly used for writing slogans. Typing paper is a thin paper for typing and copying, which is used to print documents, bills or stationery. It is divided into three grades: special number, 1 number and No.2. The quantitative range is 24 g/m2 to 30 g/m2, and the ordinary type is 28 g/m2. It requires that the thickness of the paper should not exceed 0.05 mm, the thickness should be consistent, and multiple pages can be typed and copied at one time. The paper should be strong and smooth, and it should not be soaked when writing. Color printing paper is used to print multiple subpoenas or subpoenas. Writing paper is a kind of high-consumption cultural paper, which is suitable for writing forms, exercise sheets, bills, notebook books and so on. It is divided into five grades: special number, 1, No.2, No.3 and No.4, and the quantitative range is 45g/m2 to 80g/m2. Quality requirements: white in color, smooth on both sides, dense in texture, and not soaked when writing. Gravure paper is used to print various color printed matter, periodicals, comic books, picture books, stamps and securities. Its specifications and dimensions are basically the same as newsprint, relief paper and offset paper, and it is also divided into two types: roll paper and flat paper. Gravure paper printing requires high smoothness and shrinkage, high whiteness, good smoothness and softness. Cast coated paper, also known as glass powder paper, is an advanced coated printing paper with a particularly smooth surface. It is obtained by coating the base paper twice or once with a thick coating amount (20-39g on one side). When the coating is wet, the surface of the coating is heated and dried close to the highly polished chrome-plated drying cylinder at a speed of about 100m or lower, with a gloss of about 85, and no need for calendering. Coated paper can be embossed with an embossing roller to make cloth paper or chicken skin paper. Cast-coated paper mainly prints covers, inserts and high-grade cartons, while woven paper and chicken skin paper are mostly used to print calendars and business cards. The official name of matte paper is matte coated paper. When observed in the sun, its reflectivity is lower than that of coated paper. The patterns printed with it are not as bright as coated paper.