Pre-press technology case solution (12)

Prepress production basic tutorial

Prepress operation refers to the preparatory work of the printing process, including typesetting and color separation scanning. The main task of the work lies in the mastery of the software used by the computer in prepress operations, the familiarity with the basic workflow of the printing process, and the ability to handle good graphic images.

At present, there is a very serious problem in prepress operations in China: Prepress operators are basically not printed professionals; students from printed schools basically do not understand prepress work. This creates a contradiction: how to deal with the combination of the desktop system's operation and printing expertise.

For designers who want to move from the computer graphic design industry to prepress operations, the first task is to control the printing expertise at any time after contact with the prepress work, otherwise it is very likely that the work will be impossible.

In order to help some of the designers who have entered the prepress production industry, based on previous personal work experience and experience, I briefly summarized the problems that some beginners often encounter, hoping to play a role.

First, the knowledge of characters

Text is a writing symbol used to record and convey language.

The characters used for printing can be divided into characters, fonts, font sizes, and so on.

1, font

In the domestic printing industry, the main types of characters include Chinese characters, foreign characters, and national characters. Chinese characters include, for example, Songs, bodies, and black bodies. The foreign characters can be further subdivided into white and black bodies according to the coarseness of characters, or can be divided into regular bodies, italics, and flower bodies according to their appearance. The national character refers to the characters used by some minorities, such as Mongolian, Tibetan, Uighur, and Korean.

Song-style: Song-style is the most widely used font in the printing industry. According to the different shapes of words, it is divided into the book Song and the newspaper Song. Song-style is a kind of printed font that originated from the engraving and printing of the Song Dynasty. The fonts of Song fonts are square, vertical and horizontal strokes, vertical and horizontal, angular, clear structure, neat and uniform, with strong strokes regularity, so that people have a comfortable and eye-catching feeling when reading. In modern printing, it is mainly used in the body of a book or newspaper.

Body: The body, also known as living body, is a kind of font that imitates handwriting habits. The strokes are quite uniform and well-shaped, widely used in student textbooks, popular books, and endorsements.

Black body: Black body is also called square body or isoline body. It is a stout font that is literally square. The figure is dignified, the strokes are horizontal and vertical, the handwriting is all the same thickness, and the structure is eye-catching. Blackbody applies to titles or eye-catching words or comments that require attention. Because the font is too thick, it does not apply to typographical parts.

Imitation Song Style: The imitation Song Style is a relatively elegant and straight font that adopts the structure of the Song dynasty. It is used for printing subtitles, poem essays, comments, quotations, etc., and is also used to print the text in some books. section.

Art body: Art body refers to some unusual special printing fonts, generally used to beautify the layout. The strokes and structures of the art body are generally visualized. They are commonly used on the cover of the books and magazines or on the headings of the layout. Appropriate application can effectively enhance the artistic taste of prints. The types of such fonts are very extensive, such as fonts in fonts such as Han Ding and Wen Ding.

2, font size

The font size is a measure of the size of the text. The international system is generally used as a point system. In China, the system is based on the number system, and the system is supplemented by the point system. The number system is based on the use of several types of movable type that are not multiplied by each other. It is a self-contained system based on the doubled or halved conversion relationship and can be divided into the fourth character system, the fifth character system, and the sixth character system. The smaller the nominal number of font size is, the larger the font size is. If the fourth character is larger than the fifth character, the fifth character will be larger than the sixth character.

Point system, also known as point system (P), is measured by calculating the "point" value of the word's appearance. According to the standards of the printing industry, the size of each point of the font size is equal to 0.35mm, and the error must not exceed 0.005mm. If the fifth character is replaced with the dot system, it is equal to 10.5 points, which is 3.675mm. All the outer texts are calculated by points. The size of each point is approximately equal to 1/72 inch, which is equal to 0.35146mm.

The size of the font size, in addition to the number system and point system, is the size of the traditional typesetting text. In mm, the unit is called "level (J or K)". Each level is equal to 0.25mm and 1mm is equal to 4 levels. The size of the text can be discharged from 7 to 62, and from 7 to 100. In the computer photocopying system, there is a bit of a system and a number system exists. When printing and typesetting, if you encounter a character marked with a number, you must convert the value of the number into a series to be able to grasp the correct size of the character. The conversion relationship between the number and the series is:

1J = 1K = 0.25mm = 0.714 points (P)

1 point (P)=0.35mm=1.4 level (J or K)

3, layout design and layout specifications

The layout should be based on the printing layout requirements. For example, when printing a book, you need to pay attention to the size of the book, the type of layout (horizontal or vertical), the font size of the text, the number of lines per page, the number of words per line, words and characters, and lines and lines. Intervals, the number of pages in the column and the number of words in each column, the distance between the column and the column, the placement of the page number and page number, the position and size of the header and footer, and so on.

In the text typesetting, we must also pay attention to some banned rules, such as the beginning of each paragraph to be empty two words, at the beginning of the line can not be arranged with a period, comma, burst, semicolon, colon, question mark, exclamation mark and under Quotes, lower brackets, and next-page punctuation marks cannot include upper quotation marks, upper parentheses, and uppercase names, and Chinese serial numbers such as 123, etc., numbers, years, chemical formulas, and signs before the numbers. Temperature identifiers and foreign words in single syllables should not be separated into two rows.

Second, paper

Paper is one of the important things that prepress workers need to pay attention to, and it determines the vast range of printed products.

1, the composition of the paper

Paper is a kind of material added from plant fibers to fillers, rubber compounds, pigments, and other components.

The raw materials that make up paper are straw, bamboo, cotton, and available waste. Depending on the raw materials, the nature of the formed paper will also be different.

Fillers are materials used to increase the flexibility of paper, reduce paper transparency and stretchability, and make the surface of the paper even and even, such as talc for general printing paper, kaolin for high grade paper, and barium sulfate. The use of filler should be appropriate, usually about 20% of the paper, too much will reduce the resistance and flexibility of the thread, and will hinder the absorption of ink, resulting in the powder off when printing.

The rubber compound is used to fill the small pores in the paper to improve the water resistance of the paper, and it can also improve the gloss and strength of the paper and prevent the paper from fluffing. Commonly used rubber compounds are rosin, alum and starch.

The colorants are used to enhance the color purity of paper, and most of them use inorganic pigments or organic dyes.

2, the specifications of the paper

Paper according to the different uses of the printing can be divided into flat paper and web, flat paper is suitable for general printing machine, web is generally used for high-speed rotary press.

The size of the paper is generally produced according to the standards set by the country. The paper size for printing, writing and drawing papers is: web width is divided into 1575mm, 1092mm, 880mm and 787mm; flat paper size is divided into size: 880mm x 1230mm, 850mm x 1168mm, 880mm x 1092mm, 787mm Six kinds of x 1092mm, 787mm x 960mm, 690mm x 960mm.

The standard for books and magazines and paper format size, the national regulations are to use 880mm x 1230mm, 900mm x 1280mm, 1000mm x 1400mm uncut single paper size printing. Due to equipment, production, supply and other reasons, the original 787mm x 1092mm, 850mm x 1168mm size paper can still continue to be used, but it should be noted that this size is to be phased out of the old standard format, after the paper size will be New national standards transition.

In the coastal areas, because of the large number of foreign-funded printing companies, many printing organizations still widely use some old versions of paper. Their specifications and sizes after cutting are shown in the figure.

The weight of the paper is expressed in terms of weight and weight. It is generally expressed in terms of quantification, which is what we commonly call "weight." Quantitative refers to the mass relationship of the unit area of ​​paper, expressed in g/m2. For example, 150g of paper means that the weight per sheet of this type of paper is 150g. Paper with a weight of 200 g/m2 or less (including 200 g/m2) is called "paper", and a paper with a weight exceeding 200 g/m2 is called "cardboard." The order weight refers to the total mass of paper per order (1 sheet for 500 sheets) and the unit is calculated in kg (kg). According to the paper's weight and size, the weight can be calculated by using the formula of weight (kg) = paper size (m2) x 500 x basis weight (g/m2)

Paper can be divided into industrial papers, packaging papers, household papers, and cultural papers according to different uses. Among them, cultural papers include writing papers, art papers, and printing papers. In the printing paper, it is divided into newsprint, letterpress printing paper, offset printing coating paper, dictionary paper, map and sea drawing, gravure printing paper, painting newspaper, weekly newspaper, whiteboard paper, writing paper, etc. according to the performance and characteristics of the paper. . In addition, some high-grade prints are also widely used in art-drawing papers.

Newsprint: Newsprint is mainly used for the printing of newspapers and some letterpress publications. It is soft and elastic, has strong ink-absorption capacity, and has certain mechanical strength. It can be adapted to various high-speed web presses. This kind of paper uses wood paddles as raw materials for manufacturing, contains more lignin and impurities, and is prone to yellowing, brittleness, and poor water resistance, so it is not suitable for long-term preservation.

Letterpress Printing Paper: This is a special paper used for letterpress printing. The properties of paper are similar to that of newsprint paper. Water resistance, color purity, paper surface smoothness are slightly better than newsprint paper, ink absorption is more uniform, but strong ink capacity is better than newsprint paper. To be bad.

Offset printing paper: Offset printing paper is a kind of paper used for offset (flat) printing, and it is divided into single-sided offset paper and offset-type offset paper. Single-sided offset paper is mainly used to print posters, packaging boxes, etc. Double-sided offset paper is mainly used for printing pictures, pictures, etc. Offset paper is compact in texture, less in flexibility, and strong in water resistance, and can effectively prevent the paper from being deformed, misplaced, napped, or removed from powder during multicolor overprinting. Can give the print better color purity.

Offset coated paper: also known as coated paper, is a kind of high-grade paper coated with a layer of inorganic coating on the surface of paper and then super-calendered. The surface of the paper is smooth and flat, and the color purity is high. Delicate and smooth network points can better reproduce the layered feeling of the manuscript, and are widely used in art pictures, albums, and commercial leaflets.

Gravure Printing Paper: Rotogravure printing paper is white and firm, with good smoothness and water resistance. It is mainly used for the printing of banknotes, stamps and other high quality and difficult to imitation prints.

Whiteboard paper: Whiteboard paper is a kind of paper with relatively uniform fibrous structure, surface layer with filler and rubber compound and coated with a layer of paint, and is produced by multi-roller calendering. The paper surface has high purity and relatively uniform color quality. The ink-absorption property has a good folding-resistance. It is mainly used for the packaging of goods, the lining of products, and the picture-charts.

Synthetic paper: Synthetic paper is made of chemical raw materials such as olefins and then added with some additives. It has a soft texture, strong tensile strength, high water resistance, light resistance to heat and cold, and can resist the corrosion of chemical substances without environmental pollution. Breathable, widely used in advanced art, maps, pictures, high-grade books and other printing.

4, paper performance requirements

Whether or not paper can be used for printing with high quality depends on the printability of the paper. The requirements for printing on paper are: the hue of the paper is as much as possible