Printability

First, the definition of fitness

In order to meet the needs of printing and copying quality, various requirements for manuscripts, copying, printing, processing, binding, and other processes and technologies, as well as various materials, equipment, environment, and related conditions involved, in order to obtain the best quality Everything is done.

Second, the relationship between printing and fitness

Letterpress printing: The printed part is concave and the impression is surrounded by a frame. Suitable for small amounts of forms, business cards, envelopes, stationery, self-adhesive stickers or sets of text or simple illustrations.

Lithography: The print does not protrude or sink, and the print is detailed and delicate. Suitable for multi-color prints in black and white and color books, color magazines, posters, advanced letter paper, paper boxes, calendars, newspapers, etc.

Gravure printing: There are two kinds, 1. Gravure gravure - its imprinted part has a sense of protrusion when touched by hand, the ink is thick and strong. Suitable for printing of securities and banknotes. 2. Photogravure - its imprint appears to have a faint dot-like appearance, also like continuous tone. Suitable for large-circulation color magazines, plastic films, aluminum foil and other packaging and printing materials.

Stencil printing: imprinted into burrs, thick ink layer. Hard and soft printed objects suitable for flat surfaces and curved surfaces, including plastic surfaces, large posters outside the car, printed circuit boards, partial glazing, transfer paper, and fabrics.

Non-engraving printing: Printing methods applied electronically include the use of dry toners and liquid inks. The former has a slightly convex pattern and the latter is similar to a lithographic pattern. Suitable for small lot, medium and low quality color printing or color printing.

Third, the manuscript's suitability

The manuscript, ideal conditions should include:

Write clearly and the contents of the manuscript should not be modified.

Editing contains complete edits, chapters, sections, items, etc.

Punctuation marks and paragraphs are all intact and carefully arranged.

The typo and other characters have been checked and corrected.

The form draft, ideal conditions should include:

The lines are clear and the numbers are correct.

The decimal point should be properly aligned.

The color of negative or special text and numbers should be clearly marked.

Charcoal paintings, Chinese paintings, oil paintings or watercolours, etc. The ideal conditions should include:

The level of clarity, harmony and harmony.

The color is normal and the texture is good.

The theme is correct and the performance is natural.

If the original painting is too large, it must be translated into a positive or photograph, and the color tone should be the same as the original.

Positive or photo, ideal conditions should include:

The exposure is correct and the concentration is good.

The image is sharp and beautiful.

The contrast is appropriate and the levels are rich.

Good composition and good resolution.

Fourth, the appropriateness of the replication technology

Text copy:
Due to the different type of manuscript, there are printed on the coated paper, there is written in the mold paper, there are handwriting written on the burrs or other paper, the reflectivity is not the same. Special attention must be paid to the revised exposure time when copying. The second is that the visuals of the naked eye and the copying of the plate-making camera are often slightly different. It often takes time and experience to do well.

Black and white scan over the net:
Since the density range of the original cannot often be matched with the scanner, special attention must be paid when passing through the net, especially for the concentration range and curve value (or gamma value) from the bright part to the dark part, or bright and dark color photographs. The operator's technology is different and there will be considerable quality differences. Therefore, at the time of adjustment, it is not difficult to obtain a perfect reproduction by paying attention to and comparing quality differences between manuscripts and reproductions.

Scan separation:
The control of color control and gray balance, as well as the control and adjustment of the light division and sub-light division adjustment, all require some experience in order to do a good job. Sometimes the need to make local color corrections is a difficult operation. It takes many years and months before the operation can be handy.

Manual imposition:
Before binding, the binding method must be taken into account first. Because the binding methods are different, the number and order of impositions will also be different. However, the order of binding, hardcovering and paperbacking is the same, but the distance between them is not the same. Before the imposition, you must first decide the binding mode so as to match the arrangement and the imposition. In the collage requires a page of the entire collage, can not be cut in the film, so as not to appear stripes in the printing, this situation is not easy to find in the plate, wait until the machine when printing found, and then repair with chemical liquid Or use a pumice pen to erase, not only a waste of time, but will damage the layout, and will damage the layout, and sometimes there are other problems.

Computer Group page:
Although this kind of equipment is the latest, in addition to a few large factories, there are still many printing factories that do not have the ability to purchase such expensive equipment. Although it is fast in operations, it cannot be modified after the output of the film, otherwise the film must be re-launched. Increase a lot of costs. Therefore, it is only used for making small version in China, but it does not use it to make large version. The big version still uses manual imposition. Since this operation depends entirely on computer devices, the input, storage, editing, calculation, output, and auxiliary devices are often different due to their different software systems, but the basic principles are similar.

Fifth, the suitability of printing technology

Lithography is very different from other formats. Other formats are mostly direct printing, that is, physical printing in which the printing plate is in direct contact with the paper or the printed body. The lithography is a chemical printing method using the principle of mutual exclusion of water and ink. Therefore, the applicability of other technologies is quite different from other formats.

Stack of paper:
It should be noted that the cross-threads of the paper cannot be mixed and piled together. The entire pile must have a consistent thread flow. Otherwise, the color of the printed product will change due to the paper stretching, and the product quality will not be consistent.

Ink balance:
Because the lithographic printing machine must have a wet system to supply the layout water. There are three types of systems:
1. Traditional water system. 2. Semi-alcoholic system. 3. Continuous alcohol system.
In order to make the distribution of water and ink on the printing plate average, it is necessary to make appropriate adjustments in order to obtain the best printing quality. When the ink is too much, it will cause layout pollution, too little will make the line drawing not print or incomplete. Too much water will make the ink lighter, and vice versa, it will make the wireless part of the layout stained with ink. The alcohol system should pay attention to the composition and proportion of alcohol, and it also has a great influence on quality. Although these are very important tasks in lithographic operations, it is easy to achieve the desired level as long as they actually work for a period of time.

Spraying powder:
There are two types of dusting devices:
1. Universal type. 2. Electrostatic type. Regardless of the type used, the main function is still to spray a layer of thin powder on the dry ink, so as to keep a little distance with the paper stacked on it, so as to avoid anti-printing. However, the quality of the powder and the amount of powder to be sprayed must be paid special attention. Poor quality or too much dusting will cause poor ink transfer and poor printing on the next overprint or reverse printing. Too little dusting will cause sticking of the upper and lower papers together, anti-printing and other phenomena.

Indoor temperature, humidity and air flow:
These are also the main factors affecting the printing quality. Although it is not directly related to the technology, if the temperature, humidity and air flow are changed at the top and side of the printing press, the layout water will not be easily controlled. In the past, because the cold air tuyere was on the upper left side of the printing press, the airflow on one side of the printing plate was larger than the other side. Therefore, on the large airflow side, the layout water was easier to dry and the ink-water balance operation was difficult to achieve. Printing technicians are very troubled and cannot get good print quality.

Sixth, the suitability of post-press processing

After processing:
After printing, the surface is processed with: Aqueous PVA. This is an early method. It has good transparency, good moisture resistance, and good water resistance. However, solvent-resistant ink must be used, and it has rarely been used. At present, there are more commonly used UV coating and PP, OPP plastic film, etc., film scalability, good stiffness, do not have to use high heat and high pressure, single-sided and double-sided blemishes can be, do not have to pay too much attention to the ink drying The problem is therefore the most popular one at this stage. It is divided into smooth and matte, each with its own different feelings and effects. Generally speaking, advanced book covers, book clothing, and Chinese paintings are often used for matte reproduction. For glossy books and magazines that highlight color effects, bright surfaces are often used. Only when the humidity changes, thin paper can cause curling as its disadvantage. Another bronzing process must be carefully considered before or after polishing. After the first bronzing, the glazing is protected and the gold foil is not easy to wear, but the gloss is poor. If the gilding after the first glazing is sometimes difficult after UV glazing, this must be considered in advance.

Bookbinding:
Although there are various types of binding, including hardcover, paperback, saddle-wear, threading, and binding, various types of binding have different characteristics. In the binding process, it is necessary to pay attention in advance to the requirements of the processing machinery. Preparations can only be carried out smoothly, otherwise there will be a lot of unnecessary post-order issues, such as: folding alignment, folding order, extension of binding time, unsatisfactory operations, and so on. Another hardcover, pay attention to paper and paste materials, and whether it will be after the paste due to poor absorption of the material off, but also pay attention to whether the weather is affected by changes in its quality and after the paste to be fully dry and other factors. Binding books must pay attention to the quality of the hot melt glue, and the internal pages and the cover must not come off due to brittleness.

VII. Suitability of finished products

poster:
More than a single print. The requirements for the use of paper should be not easy to stretch, and the ink used should not fade easily. Because it is often hung in the hall and is prone to wind and sun, it is best to print