Talking about printing (1)

First, the common printing process and application range

A, offset printing (lithographic printing): offset printing is a kind of lithographic printing, using pre-coated photosensitive printing plate (PS plate), the printing plate on the graphic first printed on the intermediate carrier (rubber roller), and then transferred to Indirect printing methods on substrates are the most commonly used printing methods. Lithographic printing is a printing method in which printing portions and non-printing portions of a printing plate are almost in the same plane. The printing plate includes a hydrophobic and lipophilic graphic part and a hydrophilic and oleophobic blank part. When printing, the water is applied first and then the ink is applied. In this way, the wetted printing plate has only a hydrophilic blank part of the printing plate to receive moisture, but hydrophobic. Graphic part is not water, after ink, due to the blank part of the printing plate has absorbed moisture can not be adhered to the ink, only the hydrophobic graphic part of the plate accepts the ink, and finally make the substrate and the plate directly or indirectly contact pressure Printing, the ink is transferred to the substrate to get prints.

Advantages: The plate making work is simple and inexpensive. The color plate is accurate and the printing plate is easy to copy. The print is soft in color. Can print large quantities of printing.

Disadvantages: Due to the effect of water glue during printing, the reproduction of the color tone is reduced, and the vividness is lacking. The layout ink is thin with an expressiveness of 70%.

Applications: posters, newspapers, packaging, books, magazines, leaflets, calendars, and other large-volume color prints;

B. Letterpress printing: All printing surfaces are prominent, while non-printed areas are concave, which is called relief printing.

Letterpress mainly include: movable type, paper type, lead version, thin lead version, electroplated lead plate, zinc plate, plastic plate, photosensitive resin plate, pre-coated photosensitive plate, rubber plate, flexo plate and so on.

Advantages: thick ink, bright colors, clear fonts and lines, strong ink expression, about 80%.

Disadvantages: Poor logotype affects bad lines. Platemaking is not easy to control and plate making costs are expensive. Large format prints are not suitable. Color printing is more expensive. Applicable to newspapers, packaging, forms, aluminum foil stickers and other prices must be based on the type and quantity of the specific printed species. In the days when the printing process has gradually faded out, flexographic printing in embossing has received increasing attention due to its unique environmental features.

C. Gravure Printing: The gravure printing method is gravure printing. The plate below the blank part is called gravure. There are engraving intaglio, hand-engraved gravure, electron beam engraving gravure, laser engraving gravure, photogravure, dot gravure, etching gravure, carbon paper erosion gravure, spray gravitational gravure and so on.

Hand-engraved gravure is a relatively old type of printing, mainly used for fine prints such as banknotes, securities, stamps, or some demanding prints. Special gravure printing machines and hand-engraved plates must be used. The cost of plate making is high and the time is long. Plate making and printing costs are higher than plain printing.

Other gravure plates are also complicated in the plate making process and are relatively expensive. They are not suitable for printing a small number of prints, and are mostly used for the printing of delicate colored packaging bags and luxury color magazines. General electric engraving 0.20-0.30/cm2.

Advantages: ink expression of about 90%, rich colors. Strong color reproduction. Strong layout. The number of prints is huge. The range of paper applications is extensive.

Disadvantages: The plate-making fee is expensive, the printing fee is also expensive, the plate-making work is more complicated, and a smaller number of prints is not suitable.

D. Screen printing: The printing plate is meshed, and the layout is composed of two parts: the through hole and the non-through hole. The ink is printed under the pressure of the squeegee during the printing, and the printed matter from the through hole of the screen plate is missed and printed on the substrate. the way.

Screen printing involves a wide range of fields, printing materials are complex, widely used in printing and processing all types of signs, labels, packaging containers, large posters, clothing, small electronic components. Substrates mainly involve paper (board), glass, metal, plastics, fabrics, etc. Silk screen printing has low production cost, can be produced in small batches, and has flexible procedures. It can adapt to various special environmental requirements. As long as designers can make full use of it, screen printing is actually one of the best production methods.

Other printing methods: digital printing, electrostatic laser printing, inkjet printing, transfer printing (printing head), thermal transfer (transfer film), metal printing (UV offset printing), corrugated printing (resin printing), flexo Printing (resin plate embossing), hose printing (without horizontal printing), stencil printing (glass plate printing), trademark sticker printing (resin embossing), commercial form printing (web offset printing) Carbon copy paper printing.

Second, graphic printing process and new trends

1, desktop publishing and printing process: electronic prepress or desktop publishing system, color separation and film output, proofing, imposition, printing version, version, upper version, cleaning blanket, corner line registration, ink balance, printing, folding , collation, binding, cutting, finished product.

2. CTP direct plate-making system: desktop publishing system (design, typesetting, electricity distribution), digital proofing, CTP output, upper edition, cleaning blanket, corner register, ink balance, printing, folding, collation, binding , cutting, finished product.

3, digital printing process: electronic prepress or desktop publishing system, digital printing equipment, finished products

The application of CTP direct plate making system has become a mature technology in the international field. The use of CTP process flow saves three links compared to traditional film process flow. Therefore, the production efficiency is high. The CTP platec imposition registration is accurate, does not lose the network, does not paste the plate, On the machine ink and ink balance speed, therefore, the use of the CTP version of the output version of the repeatability, the reduction of the network, or register accuracy, improve color cast, etc., have greater improvement than the use of film.

With the rapid development of digital printing technology, modern graphic printing processes are moving in a direction that more closely meets market demands. The process flow is more intuitive and accessible, the production process is more simplified, the production cycle is greatly shortened, the quality control is more precise, and on-demand printing becomes Probably, the processing technology is more abundant and diverse.

Third, pre-press production of common problems or precautions

1, the paper can not be used up when printing, to stay bleeding and mouthwash. If the paper runs out, the ink at the bleeding point will accumulate on the blanket or pressure cylinder, causing contamination.

2, some large areas of the field with a number of thin lines or shallow net in a layout, printing will cause the control of the amount of ink is difficult, the large field of the ink pattern requires a lot of ink, will lead to thicker lines; the other hand, thin lines need Less ink will result in large field colors not being saturated.

3, according to the original, design a suitable number of pages, easy binding and save paper.

4, in the printing, each additional color to pay a more cost, so the design should pay attention to the distribution of color, as little as possible the color of the pages arranged in the same version. Before embedding, a blank sheet of paper can be used to fold into a frame by the folding method of the folding machine. Write a page number on the sheet of paper to know the position. There are usually two fold and roll methods.

5. Pay attention to the rational use of overprinting and embossing.

Several common problems that should be avoided: printing is not urgent and not printed; printing of manuscripts is not completely completed and they are printed; the price is always required to be pressed as low as possible; the manuscript is not allowed to be issued at one time, and manuscripts can be freely modified at any time.

If the customer understands the graphic printing process more clearly, it will easily understand the supplier's production requirements; or communicate with the supplier and consult relevant professional opinions, so that the print can be completed more smoothly and more according to their own needs.