Pre-press technology case solution (6)

Inkjet and photo output requirements

Inkjet printing generally refers to outdoor advertising screen output, which outputs a large screen, such as the number of billboard screens next to the highway is the output of the inkjet printer. Output models are: NRU SALSA 3200, Choi Shen 3200, etc., generally the maximum width of 3.2 meters. The media used in the inkjet printer is generally advertising cloth (commonly known as light box cloth). The ink uses oily ink. In order to ensure the persistence of the picture, the color of the screen is generally a bit darker than the color on the display. Its actual output image resolution generally only needs 30~45DPI (according to the printing requirements), the actual size of the screen is relatively large, there are more than 100 square meters of area.

The photo is generally used in the home, and the screen it outputs is generally only a few square meters in size. For example, the small advertisement screen used by manufacturers at the exhibition. Output models such as: HP5000, generally the maximum width of 1.5 meters. The media used in the photo machine is generally PP paper and light sheet, and the ink uses water-based ink. After the output image is finished, the film and the sampan plate are counted as finished products, and the output resolution can reach 300-1200 DPI (different in different models), and its color is relatively saturated and clear.

Below we briefly describe some simple requirements for making and exporting images in inkjet and photo.

1, size:
The size of the spray image is the same as the actual required screen size. Unlike printing, it does not require bleeding. After the inkjet company has left blank edges after outputting the screen, the general situation is to leave 10CM at the edge of the net screen. As shown in the figure, you can negotiate with the inkjet output company, leaving a certain number of sides to use to make a buttonhole. The price is calculated per square meter, so the screen size is in centimeters.

2, image resolution requirements:
Inkjet images are often very large, and it should be understood that "deep in Sheshan does not know what it is." The same is true for the spray painting. If the big screen still uses the resolution of the print, it will be exhausting the computer. However, there are no standard requirements for spray image filtering. Here are the resolutions I use when using different sizes. You can refer to:

Image area (square meters) 180 - infinite 30---180 1 - 30
Resolution (dpi) 11.25 22.5 45
Note: Because the current inkjet printers mostly require 11.25 DPI, 22.5 DPI, and 45 DPI for the output image, rational use of the image resolution can speed up the drawing process.
The general situation of the photo requires 72DPI/inch. If the image size is too large (such as when the PHOTOSHOP new image shows the actual size when the file size exceeds 400M), the resolution can be properly controlled within 400M.

3, image mode requirements:

Inkjet uses the CMKY mode in a unified manner, and the use of the RGB mode is prohibited. Today's inkjet printers are all four-color inkjet printers, and their color is very different from the color of the printer. Of course, when printing, the printer will follow the printing standard. The inkjet company will adjust the screen color and sample size.
Photo can use CMKY mode or RGB mode. Note that the red value in RGB is defined by CMKY, ie M=100 Y=100.

4, the black part of the image requirements:

Single black values ​​are strictly forbidden in inkjet and pictorial images, and C, M, and Y colors must be added to form a mixed black. If it is big black, it can be made: C=50 M=50 Y=50 K=100. Especially when using the effects it brings in PHOTOSHOP, pay attention to changing the black part to four-color black, otherwise the black part will have cross bars on the screen, which will affect the overall effect.

5, image storage requirements:

The inkjet and photo-realistic images are best stored in TIF format, but note that the compressed format is not available.
The number of points depends on the circumstances. General inkjet 30dpi, 72dpi general photo, if the screen is large, can be reduced accordingly. The minimum number of points I have made is 10dpi, 300 square. If you are too big, you can do it in several sections. The photo is generally no less than 50dpi. With regard to the small number of points, the screen will not be blurred, but will produce strong jaggies. On the contrary, if you increase the number of points and increase the size of the image, it will become blurred, and there will be less obvious jaggies. If you do it in general, you can think twice about it.

Regarding the compression format, the general inkjet company requirements are in tiff, cmyk format. Its practical jpg is not a bad idea, but the compression ratio must be higher than 8, otherwise the picture quality is not guaranteed. If the original image is small, blurring may be increased in an appropriate amount.

25-30 points is enough to spray our company is Israel's Sagittarius, and the United States Wit the last point of the inkjet printer is 23.125 (Witter's). When you make a big point on the map when the machine will also Reduce the number of points. It is better to use CMYK because of the difference between inkjet and RGB display. We are not all the first to the customer to see the sample before it is scheduled to spray it? Use CMYK to sample if the customer accepts it then spray out There will be no problem

The machine is 3.2 meters. I have done the minimum 13.3 resolution. 330 square meters. Leave 5 cm white cloth. Most of my installations use 30mm or 25mm square tubes, which should be fine. I think the colors of RGB should not be CMYK accurate. I use RGB only for my photo.

Zoom in on the PS to 100% (actual output size), see if your font is jagged, and if the background is too flat, others will read it based on your own experience. In fact, the background is not too important. The text should not be serrated with 100% display. It is true, oh, some fonts are magnified after zooming in, and other similar fonts are better. ~ Suggested use of Founder ~

screen printing

Part of the holes of the screen printing plate can penetrate the ink and leak onto the printing material; the mesh of the rest of the printing plate is blocked and cannot pass through the ink, blanks are formed on the printing material, and the screen is used as the supporting body. Screen stretched on the frame, and then coated with sensitized film on the Internet, the formation of photosensitive film, and then the positive version of the bottom plate close on the printing plate exposure, the exposure. Developing, the part of the plate that does not need to pass the ink receives light to form a cured film, the mesh is sealed, the ink is impermeable to the printing, the mesh of the part that needs to pass the ink on the printing plate is not closed, and the ink is penetrated during printing. Black marks formed on the substrate. Silk screen ink is relatively thick, poor color performance, if you want to get better results, you can increase the number of mesh, at least more than 300 mesh / inch. There are generally no requirements for production, and quality can be met, unlike offset printing or embossing.
Screen printing features:

1. Not subject to the size and shape of the substrate. In general, printing can only be carried out on a flat surface. Silk screen printing can not only be printed on a flat surface, but can also be printed on shapes and concave and convex surfaces of special shapes. It can also print a variety of large-scale advertisement paintings, curtains, and curtains.
2. The layout is soft and small. Screen printing plate is soft and flexible, and the printing pressure is small, so not only can it be printed on soft substrates such as paper and textiles, but also can be easily damaged by pressing glass. Printing on ceramicware.
3. Thick ink layer coverage. Screen printing ink thickness up to 30 ~ 100μm, therefore, the hiding power of ink is particularly strong, can be pure white printing on black paper.
The thickness of the screen printing ink is strong, and the three-dimensional printing image is strong, which is unmatched by other printing methods.
4. Suitable for all types of inks. The wide range of inks used in screen printing has exceeded the scope of the usual ink definition. Actually, there are pastes, plastics, paints, adhesives, or solid powders. Therefore, screen printing inks are sometimes collectively referred to as "printing materials."
5. Strong light resistance. The problem of ink classification in a broad sense should be classified according to the type of printing, namely, letterpress ink, lithographic ink, gravure ink, and filtered ink. However, such classification is too principled to express all realities. In recent years, due to the ever-increasing variety of inks, new designs have appeared continuously. There are limitations only because of the type.

In addition to classification by type, there are generally classified by dry type. Examples include oxidatively drying inks, osmotic drying inks, volatile drying inks, and freeze drying inks.

There are also classified by product use. Such as book inks, printing inks, glass inks, plastic inks and so on. Also classified by product characteristics. Such as security ink, bright ink, photosensitive ink, transparent ink, electrostatic ink and so on. He also often hears the name of alcohol (soluble) ink and water (soluble) ink, which is a way to reflect their characteristics.

First, Offset Ink: In the future, the demand for the market will increase steadily, and the increase will not be too large, which will increase at a rate of 5% to 6%, accounting for 40% to 45%, of which the offset inks The growth rate will be faster.
Second, letterpress ink: the overall proportion will drop, but the proportion of flexographic ink will continue to rise, which is also in line with the United States and Japan and other developed countries.
Third, gravure ink: in a steady state, but the plastic ink in the printing and the table is an upward trend, far from the international trend is different, because far involved in environmental recovery and other issues.
Fourth, the mesh version of the ink: the increase in market sales, mainly the increase in the amount of metal, glass and plastic screen printing ink. Moreover, the screen printing equipment has broken the backward situation of the manual printing machine. In these areas, advanced screen printing equipment has been used to increase the screen ink usage.
5. Dedicated special inks: There will be more and more dosages, such as ink for printing inks, anti-counterfeit inks, pearlescent inks, signage inks, fluorescent inks, and phosphorescent inks, etc., which will increase their usage due to future market demands.

Scanner color separation basic requirements

1. Bright and colorful.
2. Strong contrast.
3. Emphasize clarity.
4. Under color removal. In the color printing process can also be used to reduce the amount of ink to reduce the amount of ink
5. Since manuscripts are influenced by time, transmission, and many factors of the equipment, this requires the operator to have a certain aesthetic view, so that the overall color picture should not be distorted, the color should be close to its real effect, and the black and white fields of the picture should be set. The extremely high light area of ​​the area can be net-free, but the large-area part must not be netted, and the dark-tone area should be kept at the level.

Comparison of traditional proofing and digital proofing techniques

Traditional proofing digital proofing

The color of the relative printing effect is poor, the color difference is good, and the color difference is small

Image reproduction performance

Good image resolution (overprinting accuracy)

Proof consistency is poor

Slow output speed

The proofing format can be large or small

Lower system cost is lower

Personnel requirements high and no special requirements

Others need color separation output, printing version does not need

Large floor space

High environmental requirements, no environmental special requirements

Initially, proofing was done on the printing press by printing plates (print plates and impression cylinders). From a technical point of view, only really outstanding proofs can be called proofing.

Of course, proofing on the press is not profitable. Therefore, people are looking for more favorable proofing methods - printing proofs on roll paper and flat proofers. In order to simulate the results of an actual production press, the proofing conditions must be closer to the actual printing conditions.

Later, people began to use reproducible proofing methods, but these methods can only be a substitute for proofing, because it is no longer printed on the official printed paper with ink, but with pigments and other pigments in the synthetic material. The proofs are printed on the carrier. German called this proofing method "Proof," but in the English vocabulary, the meaning of the word is completely different.

English "Proof" is all proofing methods, German means "color proofing", and color proofing is divided into "colored material proofing" and "non-material color proofing." The corresponding English names are "hard proof" and "soft proofing." "Hard copy proofing" is further divided into "machine proofing" and "offset proofing machine proofing". The corresponding German names are "proof proof" and "proof proof substitute". Analog proofing substitutes are produced by film and digital proofing substitutes are produced by digital data.

C: 100 M: 0 Y: 0 K: 0 The printed color is light and green. What kind of value can be changed to be better?

The printer is "ink", it is water-based, the printing is "ink", it is oily, correct