Knowledge of printing plate colors and fonts

Knowledge of printing plate color and font When printing plate-making, the manuscript should be divided into four colors: cyan (C), magenta (M), yellow (Y) and black (K). What is the color separation principle?
There are thousands of colors on the picture of color picture album or color photo. It is almost impossible to print these thousands of colors one by one. Four-color printing is adopted in printing. That is to say, the original is first color decomposed into cyan (C), magenta (M), yellow (Y) and black (K), and then color synthesis is performed when printing. The so-called “color separation” is based on the principle of subtractive color method, using the selective absorption characteristics of red, green and blue color filters for different wavelengths of color light, and decomposing the original into three primary colors: yellow, magenta and cyan. In the process of color separation, the color light absorbed by the color filter is the complementary color light of the color filter itself, so that the negative film of black-and-white image is formed on the photosensitive film, then screened to form the dot negative film, and finally copied and dried into various printing plates. This is the earliest principle of photographic color separation.

Due to the development of printing technology, we can now separate and sample the original color by pre-press scanning equipment and convert it into digital information, that is, we can decompose the original color into red (R), green (G) and blue (B) by the same method as photo-making, and digitize it, and then use the computer to decompose the digital information into cyan (C), magenta (M), yellow (Y) and black by mathematical calculation 1. the printed color pages should be saved in PSD format, and the bleeding value should be adjusted. the resolution of the picture should be 300 pixels/inch, otherwise the printed image will not be clear, and the image should be in CMYK mode.
2. Version, not all formats can be output. Different versions, even the difference between the Chinese version and the simplified Chinese version may lead to the inability to output; 3, color, all printing plants will require you to use CMYK color mode, but the output company can use RPG output; 4. Format, TIFF format and JPG mode are common in most cases, and can be used when the versions are incompatible; 5. The resolution should not be too low, 150-300, and be as high as possible.
Pre-press operation refers to the pre-work of printing technology, including typesetting, imposition, color separation and scanning, etc. The importance of its work mainly lies in mastering the software used by computer in prepress operation, being familiar with the basic workflow of printing technology, and having good graphics and image processing ability.
First, the character knowledge Words are written symbols used to record and convey language. Characters used in printing can be divided into word types, fonts, sizes, etc.
1. Font In the domestic printing industry, there are mainly Chinese characters, foreign characters and national characters. Chinese characters include Song Style, Regular Script, Bold Type and so on. Foreign characters can be divided into white body and black body according to the thickness of characters, or into regular body, italics, flower body and so on according to the shape. Ethnic characters refer to the characters used by some ethnic minorities, such as Mongolian, Tibetan, Uighur and Korean.
Song typeface: Song typeface is one of the most widely used fonts in printing industry. According to the different shapes of characters, it can be divided into Shu Song and Bao Song. Song Style is a common printing font originated in Song Dynasty. Song typeface is square, with horizontal and vertical strokes, fine and thick, sharp edges and corners, rigorous structure, neat and uniform, and strong stroke regularity, which makes people feel comfortable and eye-catching when reading. In modern printing, it is mainly used in the main body of books and periodicals or newspapers.
Regular script: Regular script, also known as living body, is a font imitating handwriting habits, with neat and even strokes and correct shapes, which is widely used in students’ textbooks, popular reading materials and annotations.
Blackbody: Blackbody, also known as square or isoline, is a stout font literally square, with dignified font style, horizontal and vertical strokes, uniform thickness of handwriting and striking and tight structure. Bold type is suitable for titles or eye-catching comments or annotations that need attention. Because the font is too thick, it is not suitable for typography.
Imitation Song Style: Imitation Song Style is a relatively delicate and upright font with Song Style structure and regular script strokes. The strokes are uniform in thickness, which is often used for typography of subheadings, poetry essays, annotations, quotations, etc. It is also used for typography of the main body in some reading materials.
Art style: Art style refers to some abnormal special printing fonts, which are generally used to beautify the layout. Generally, the strokes and structures of art style have been visualized, which are often used in the title part on the cover or layout of books and periodicals. Appropriate application can effectively enhance the artistic taste of printed matter. There are a wide range of fonts, such as those in Han Ding and Wen Ding.

Understand printing Pre-press operation refers to the pre-work of printing technology, including typesetting, imposition, color separation and scanning, etc. The importance of its work mainly lies in mastering the software used by the computer in prepress operation, being familiar with the basic workflow of printing technology, and having good graphics and image processing ability.
For designers who want to transfer from the computer graphic design industry to the prepress work, the first task is to control the printing expertise at all costs after being exposed to prepress work, otherwise it is very likely that they will not be able to work.
First, the character knowledge Words are written symbols used to record and convey language. Characters used in printing can be divided into word types, fonts, sizes, etc.
1. Font In the domestic printing industry, there are mainly Chinese characters, foreign characters and national characters. Chinese characters include Song Style, Regular Script, Bold Type and so on. Foreign characters can be divided into white body and black body according to the thickness of characters, or into regular body, italics, flower body and so on according to the shape. Ethnic characters refer to the characters used by some ethnic minorities, such as Mongolian, Tibetan, Uighur and Korean.
Song typeface: Song typeface is one of the most widely used fonts in printing industry. According to the different shapes of characters, it can be divided into Shu Song and Bao Song. Song Style is a common printing font originated in Song Dynasty. Song typeface is square, with horizontal and vertical strokes, fine and thick, sharp edges and corners, rigorous structure, neat and uniform, and strong stroke regularity, which makes people feel comfortable and eye-catching when reading. In modern printing, it is mainly used in the main body of books and periodicals or newspapers.
Regular script: Regular script, also known as living body, is a font imitating handwriting habits, with neat and even strokes and correct shapes, which is widely used in students’ textbooks, popular reading materials and annotations.
Blackbody: Blackbody, also known as square or isoline, is a stout font literally square, with dignified font style, horizontal and vertical strokes, uniform thickness of handwriting and striking and tight structure. Bold type is suitable for titles or eye-catching comments or annotations that need attention. Because the font is too thick, it is not suitable for typography.
Imitation Song Style: Imitation Song Style is a relatively delicate and upright font with Song Style structure and regular script strokes. The strokes are uniform in thickness, which is often used for typography of subheadings, poetry essays, annotations, quotations, etc. It is also used for typography of the main body in some reading materials.
Art style: Art style refers to some abnormal special printing fonts, which are generally used to beautify the layout. Generally, the strokes and structures of art style have been visualized, which are often used in the title part on the cover or layout of books and periodicals. Appropriate application can effectively enhance the artistic taste of printed matter. There are a wide range of fonts, such as those in Han Ding and Wen Ding.
2. Font size Font size is a measure to distinguish the size of characters, which is generally used internationally, while the number system is the main one in China, supplemented by the dot system. Number system is based on several types of movable type which are not multiples of each other, and forms its own system according to the conversion relationship of doubling or halving, which can be divided into four-word system, five-word system and six-word system. The smaller the nominal number of the font size, the larger the font size, such as No.4 is bigger than No.5, and No.5 is bigger than No.6, etc.
Point system, also known as point system (P), is measured by calculating the “point” value of the shape of a word. According to the printing industry standard, the size of each dot value of the font size is equal to 0.35mm, and the error shall not exceed 0.005 mm. For example, if the No.5 character is changed into the dot system, it is equal to 10.5 dots, that is, 3.675 mm. All external characters are calculated in points, and the size of each point is about 1/72 inch, which is equal to 0.35146 mm.
In addition to the number system and dot system, the size of font size is the size of traditional typesetting. The unit of calculation is mm, which is called “grade (j or k)”. Every level is equal to 0.25mm, and 1mm is equal to level 4. The size of typesetting characters can be discharged from grade 7 to grade 62, and also from grade 7 to grade 100. In the computer phototypesetting system, the dot system also has the number system. In printing and typesetting, if characters marked with numbers are encountered, the numbers must be converted into series, so that the correct size of characters can be grasped. The conversion relationship between number and series is:
1J = 1K =0.25mm = 0.714 points (p) 1 point (p) = 0.35mm = class 1.4 (j or k) 3. Layout design and typesetting specifications When typesetting, the layout should be designed according to the requirements of printing layout. For example, when printing a book, attention should be paid to the size of the book, the form of typesetting (horizontal or vertical), the font size of the text, the number of lines per page and the number of words per line, the gap between words and lines, the number of columns and the number of words per column, the spacing between columns, page numbers and their placement, the position and size of headers and footers, etc.
When typesetting, we should also pay attention to some prohibition rules, such as leaving two characters blank at the beginning of each paragraph, not putting a full stop, comma, pause, semicolon, colon, question mark, exclamation mark, punctuation marks such as quotation marks, brackets, book titles, etc. at the beginning of the line, and not putting quotation marks, brackets, book titles and serial numbers in Chinese such as ① ② ③ at the end of the line.

Second, the paper Paper is one of the important contents that prepress workers need to pay attention to, which determines the great range of printed products.
1. composition of paper Paper is a kind of material which is processed by adding fillers, sizing materials, pigments and other components into plant fibers.
The raw materials of paper mainly include straw, bamboo and wood, cotton and hemp, and usable waste materials. According to different raw materials, the properties of the paper will be different.
Fillers are materials used to increase the flexibility of paper, reduce the transparency and flexibility of paper, and make the surface of paper smooth and even, such as talcum powder for general printing paper, kaolin and barium sulfate for high-grade paper, etc. The use of filler should be appropriate, generally accounting for about 20% of paper. Too much filler will reduce the resistance and flexibility of thread, and will hinder the absorption of ink, resulting in powder loss during printing.
The purpose of sizing is to fill the small pores in the paper, so as to improve the water resistance of the paper, improve the glossiness and strength of the paper, and prevent the paper surface from fuzzing. Commonly used sizing materials include rosin, alum, starch, etc.
Pigment is to enhance the color purity of paper, and most of them use inorganic pigment or organic dye.
2. Specifications of paper Paper can be divided into flat paper and roll paper according to different printing purposes. Flat paper is suitable for general printing machines, and roll paper is generally used for high-speed rotary printing machines.
The size of paper is generally produced according to the national standards. The size of base paper for printing, writing and drawing paper is: the width of roll paper is divided into 1575mm, 1092mm, 880mm and 787mm; According to the size, the base paper of flat paper can be divided into six types: 880mm x 1230mm, 850mm x 1168mm, 880mm x 1092mm, 787mm x 1092mm, 787mm x 960mm, 690mm x 960mm, etc.
The national standard for the format of books and magazines and the size of paper is to print with uncut single paper sizes of 880mm x 1230mm, 900mm x 1280mm and 1000mm x 1400mm. Due to equipment, production, supply and other reasons, the original paper sizes of 787mm x 1092mm and 850mm x 1168mm can still be used at present, but it should be noted that this size is the old standard version to be phased out, and the paper size will transition to the new national standard in the future.