Basic knowledge of printing (3)

Print classification

The ultimate product category

Offices: Refers to office-related prints such as letter paper, envelopes, and office forms.

Publicity: Refers to posters, leaflets, product brochures, and other printed materials related to corporate publicity or product promotion.

Production category: refers to large quantities of printed matter directly related to the production of products, such as packaging boxes and adhesive labels.

Classified by printing press
Offset printing: refers to lithographic printing, used for printing on four-color paper.

Gravure printing: refers to gravure (usually refers to the steel version) printing, used for plastic printing.

Flexographic printing: refers to the use of flexible materials (usually refers to the resin plate, etc.), used for stickers printing.

Screen printing: It can be printed on various materials and used for gift printing.

Classification by material
Paper Printing: The most commonly used printing.

Plastic printing: Mostly used for printing bags.

Special materials: Printing refers to the printing of glass, metal, wood, etc.

Appropriate and reasonable selection and use of paper is of great importance for ensuring the quality of publications and reducing the cost of publications. As a person in charge of material management in the publishing and printing industry, not only should the types and specifications of the required papers be selected in advance according to the publication plans of the various annual and quarterly divisions of the department, but also the amount of various papers required in the publication plan can be accurately calculated. It should also be able to coordinate and guide the printing staff in the rational use of paper in order to reduce paper consumption and increase economic efficiency.

(1) Selection of paper The selection of paper includes several aspects such as selection of varieties, specifications and quality grades. It is not possible to focus on one aspect but neglect other aspects.

When selecting a paper type, it is mainly necessary to select according to the characteristics of the printed material to be printed and the type of printing machine used. Double-sided coated paper or offset paper can be used for color covers, illustrations, or ad inserts in printed books and magazines; single-sided coated paper or single-tape paper can be used for single-sided prints such as trademarks; printed dictionaries, dictionaries, manuals, and other tools The book should use dictionary paper or thin letterpress paper; printing general books can use offset book paper or letterpress paper. It is also a general book for printing. If you want to use it on a rotary press, you need to use web (except flatbed printers). If you plan to print on a general platform, you need to use flatbed paper; if you print on an offset press, you should use offset paper, If you print on a letterpress printing press, you can use letterpress printing paper.

There are many kinds of prints, and the type of paper used must be selected according to the specific characteristics of various prints.

The selection of paper specifications involves the opening of books and papers. Therefore, it is necessary to introduce paper-opening methods and commonly-used papers for general books and periodicals.

The paper produced by the paper production department in accordance with national standards is called full-open paper. A full-open paper is cut or folded into small pieces of equal area, and the number of open pages is called. The specifications of various types of publications have a uniform standard across the country. Therefore, the books printed in all parts of the country are of the same size.

Because the sizes of various sizes of paper are not the same, although they are all cut to the same opening size, their size and specifications are not the same. After the books are booked, it is inaccurate if they are collectively referred to as the number of copies. China currently uses 787*1092 (mm) paper as a standard print. It is used to print a 32-page book called 32-copy book. If a 32-page book is printed on 850*1168 (mm) paper, because the paper size is larger than the standard print, a "big" word is called, which is called a large 32 book.

The selection of the open book is generally based on the nature of the book, the number of pages, the level of the reader, the conditions of use, and other factors. There is no hard and fast rule. Most of the books and periodicals are cut in a geometric progression of 2 so that they can be folded into books using the machine during binding. The more common ones are 16, 32, and 64, and the most commonly used is 32 copies.

The geometrical series opening method of the lower knife in the longitudinal direction is also a basic opening method that is commonly used, ie, the straight opening method. In accordance with the geometric progression of 2 cut, you can also start the knife in the width direction, which is the so-called horizontal open method.

Cross-rolling method is rarely used, only certain covers, inserts and special paper for prints, adopt this method.

In order to meet the special needs of publication, deformed versions of non-geometric series are sometimes used, such as 12-open, 18-open, 20-open, 24-open, 28-open, and 36-open. The malformed copy can't be folded with a machine, and the material is too cumbersome to be opened. Manual operations are used during binding, and errors are likely to occur. Therefore, general books and periodicals, especially books with a large number of prints, are rarely used. There are three open methods, five open methods, and seven open methods.

With the same number of open and open-book printing books, the size and area of ​​the copy vary with the specifications of the selected paper, so pay attention to the specifications of the paper when selecting the paper. In general, more authoritative documents or social celebrities often use 850*1168 (mm) large-format paper, and most novels and other ordinary books use 787*1092 (mm) standard paper. There is also an internationally more common specification 880*1230 (mm), which has been officially included in the national standard.

When selecting the paper specifications, besides paying attention to the size of the paper, select the appropriate ration. Generally, under the premise of satisfying printing and usage requirements, papers with a smaller basis weight should be selected as far as possible, which can reduce the cost of publications.

After selecting the type and specification of the paper used, the quality level of the paper must be carefully selected. In other words, it is necessary to be familiar with the characteristics and quality of various products of various paper mills, and to keep abreast of and understand their changes.

After the selected paper types, specifications, manufacturers, and quality levels have been determined, it is also important to note that it is best to use the products produced by one manufacturer in the same period to print the same book in the printing process. Otherwise, due to the large differences in the color of the same type of paper produced by different manufacturers at different times, the phenomenon of "sandwiching" will occur in printed books.