Color advertising prepress must be considered after the process

Newspaper advertising, as a major method of advertising communication, has been widely known to all walks of life in the society and has been widely adopted. However, most advertising design and production staff do not understand the printing method of newspapers. Pay attention to the subjective visual effects, and send the designed data files directly to the newspaper publishing and printing. The comrades of the advertising department of the newspapers know about the post-printing procedures, but they dare not easily change the documents sent by the customers. The problem came out. Due to the rough surface of newsprint, the low degree of glue application or even the lack of sizing, the strong ink permeability, the serious dot expansion, and the low overprinting rate, we always had problems in the printing of advertisements.

At present, the main problems in our newspaper's advertising printing are the following: First, some outlets in the middle tone are enlarged, resulting in the prone to color cast; Second, the gray component is not enough to replace, and when the four-color overprint, the color blocks are not uniform; As a total amount of ink restrictions, resulting in serious filthy dirt, the fourth is difficult to register small words. This may seem like a few problems, but the analysis is a problem, that is, there is no targeted selection of settings in the image processing output. Since most companies make only one data file during the production of advertisements, the same design manuscript has passed many methods to spread the advertisement, such as billboards, periodicals, magazine advertisements, newspaper advertisements, or corporate self-published publications. Among these transmission methods, the media they use varies greatly. For example, billboards are mostly printed (or printed on large-format printers). Journals, magazines, etc., although they are print media, use large paper. Differently, there are coated papers, offset papers, newsprint papers, current light-coated papers, and different papers. Their printability is also different. Advertisers often overlook this, so we often see the same advertisements. The color, sharpness and visual impact of design manuscripts displayed in different flat media vary greatly. The advertisements for Toyota Yaris and Toyota New Camry may be used as examples in this article. Both of these car advertisements use full-page black as the background. Perhaps it is necessary to highlight the effect of passing out of the world to enhance the visual impact on readers. Reading from the soft-proofing of the screen, the total sum of the four-color values ​​of CMYK can reach a maximum value of more than 380. This can be printed for coated paper, but for newsprint, the total amount of ink is generally only 260, so it is difficult to grind dirt. Avoiding, at the same time, due to the low trapping rate, the printing of the color blocks is not easy to be uniform, and the printing effect is not ideal.

So, can this situation change? We believe that it is impossible for different printing materials to have no chromatic aberration at all, but we can minimize this chromatic aberration. One way to do this is to strengthen the advertising design staff. After the process of printing knowledge to understand, after the design of the advertising manuscript according to different paper save different data files, the difference is: in the image processing software, in the color separation parameter settings, for different paper, different ink , set different standards, such as inks are American standards, European standards, Japanese standards; paper is divided into coated paper, non-coated paper, newsprint, etc., and for different paper, set different dot gain rates, and gray components Replace GCR or background color to remove UCR, gain or background gain UCM, and set the total ink volume limit and the maximum black volume.

The specific operation is: Open PHOTOSHOP software, click on "Edit - Color Settings" in the pop-up window, select "Settings - Custom" workspace items, RGB column according to the display used for selection, "CMYK" select "Customize "CMYK", in the lower menu, "Ink Color" and "Extending Dots" in "Ink Options", select "COATED,UNCOATED," according to the printing materials used, either coated or uncoated or newsprint. "NEWSPRINT" option, the dot expansion is based on the different paper settings above, there are selectable curve items for accurate measurement of prints, and quasi-determined values ​​for different network expansion percentages, without the criteria for the selection criteria, but if For newsprint printing, the percentage value behind it shall be 25%~30%. In the “Separation” option, the color separation type selects “GCR” or “UCR” according to different substrates, and newsprint printing generally selects GCR, Black Edition. Produce the selection "medium", black ink limit value of 100 or 85, "ink total limit" item, if coated paper is printed at 400, non-coated paper is printed at 300, new Paper printing takes 260. At the same time, if the total amount reaches 260, then the upper black ink limit value should be 85. The UCA value is generally used when the coated paper printing is used to increase the thick feeling of the ink layer, and is used when printing on non-coated paper. Take 0”. So we can get design original data files for different printing materials, and deliver different files for different advertising channels.

The following analysis of three situations.

Scenario 1 Ink is a European standard. The paper is coated paper, and the dot gain rate is 9% at 50%. GCR processing. However, the black plate is generated as 0, so the total ink volume reaches 400 at the maximum, and there is no black ink limit. The UCA value is an appropriate value according to different conditions. This is applicable in the case of coated paper, ie, coated paper.

Case 2 The ink is of Japanese standard, and the paper is uncoated paper. At this time, the dot gain at 15% is 15% at the 50% point and the GCR is processed. Black version can be selected according to different circumstances "low" or "middle", black ink limit is 100, the total ink limit is 300, UCA number is 0.

Scenario 3 Ink is U.S. standard, paper is newsprint, 30% of outlets are expanded at 50%, and GCR is processed. The ink plate produces “medium” or more, the black ink is limited to 100, the total ink volume is limited to 260, the UCA quantity is 0, and newsprint has an additional condition that when the total amount of CMYK four-color ink reaches 260, the black Edition cannot exceed 85%.

With the above three different color separation parameter settings for the same manuscript, how much the GCR (UCR, UCM) replacement amount changes, the percentage of dot area that can be used for different paper printing can be made when making a plate. This is for different paper printing. The inconsistent dot gains and the offsets made in the prepress segment, such as the substitution of newsprint papers, can change some four-color overprints into tri-colors or even two-color overprints. This is the color reproduction and registration of the production process. It is much more beneficial, and precisely because of the existence of such ideas, we have a professional color management system that we are now booming.

Through the above analysis, we should be able to draw nine combinations of inks (U.S., Europe, Japan) and paper (coating, non-coating, newsprint) for each of the three criteria, plus the increasing use of commercial rotation nowadays. Lightly coated paper can have 12 kinds of combinations, that is, the same advertisement to save 12 kinds of data files, this is a bit more tedious, we can determine an ink according to which ink is commonly used, and then according to different papers are saved as Coated paper printed documents, non-coated paper printed documents, light coated paper printed documents and newsprint printed documents, a total of four file versions were placed on different advertising and dissemination carriers, so as to ensure the same advertising in a variety of paper printing effect It may be close, technically speaking, this is a very simple technique, and the problem is that most of the current advertising design staff do not pay attention to this problem because they do not understand the printing process, or from a customer point of view, To deliver a product, a printing and processing plant must print the effect he needs. This is not true for some high-end or exquisite advertising prints. Any influence, but there are many hidden dangers for the printing of newspapers, how the relevant departments of newspapers and advertisers to strengthen communication, from the technical level to solve the problem has become an important way, and from the newspaper itself, in the current financial crisis Under the background, how to use existing technologies to speed up the dataization process of the entire process, enhance the ability to respond to various possible problems, avoid drastic shrinkage of the advertising market, and meet the increasingly high quality requirements of customers, is also an urgent matter. .