For long-term printing professionals, some printing errors are objective and unavoidable, while for customers who receive printed products and play a decisive role in the acceptance of finished products, sometimes they are not fully aware of these errors. As a result, communication between the two sides is very difficult after disputes arise. Customers think that the finished products of the printing plant are not up to standard, but they are making excuses and arguing unreasonably. Printers think that customers are making unreasonable trouble and have problems in payment creditworthiness.
This article briefly introduces the objective errors in printing. The reason why it exists objectively is due to the limitation of the machine itself, and these errors are unavoidable, rather than due to human factors, such as inadequate management, inappropriate quality control and other factors. These errors include:
1. text error in typesetting:
Typesetting is an important process before printing. To be exact, typesetting is a typesetting work which is done by the designers and producers using the corresponding software at the request of the customers. Therefore, from the point of view of the printing plant, before printing, customers are usually required to sign for confirmation. Sometimes, however, due to the time constraints of the letterwork and the degree of trust between the two parties, customers may completely delegate the right of typesetting confirmation to the printing plant. In this case, once problems arise, customers may blame the design and production personnel for irresponsibility, such as typographic errors or other typographic errors.
It should be said that the occurrence of such errors is not caused by the mechanical problems mentioned above, but by the problems of process control. Therefore, we generally require the signature confirmation of the customer before the proofing. These errors can be reduced or eliminated to a large extent by mutual comparison. But even so, in fact, there may be some mistakes in the client's confirmation.
In this regard, we recommend drawing lessons from the practices of some multinational corporations, which generally follow the rigorous principle of marking "this information is for reference only, and the company does not bear any responsibility for the mistakes made in the printed matter" in order to eliminate the joint and several liability caused by typesetting errors.
2. out of print and proofing error:
After the designer and producer have finished the typesetting work, they enter the process of production and typesetting, which is what we usually call the proofing. Generally speaking, the accuracy of laser Phototypesetter is in the range of 0.01 - 0.1 mm. At the same time, because of the different film, it will lead to a certain error.
The most direct manifestation of this error is that in four films (black, red, yellow and blue), if a film (such as black version) has problems and needs to be patched, because the film output may be different, the resolution may be different (not in the same batch of films), thus leading to dot changes, the film may be patched with the same film. The first three films were not allowed to register. Therefore, we should try our best to shape once the film is released and minimize the patch. Of course, the scrambling code or font changes due to font replacement can be avoided if the relevant personnel are seriously responsible.
After film (film) production, traditional analog proofing needs to use a set of four films for proofing. In proofing, in order to achieve the accuracy and stability of the color of the four-color ink sample, we must control and standardize three links, namely, equipment, materials and quality standards. In equipment, it is necessary to adjust the pressure, plate temperature and air cushion rubber cloth of the proofing machine in order to ensure that the proofing machine is in the best working state; in materials, the same brand and a series of inks should be standardized, and four-color inks with different brands should be used, which will result in different characteristic documents between the sample and the scanner, and direct shadow. Calibration accuracy.
In addition, paper should be standardized. In principle, proofing and printing should use the same kind of paper; in terms of quality standards, attention should be paid to the field density value and the relative contrast value of printing. If these factors can not be taken into account, it will lead to errors in printing products compared with proofing. For example, printing ink is different from proofing ink; printing paper is different from proofing paper (such as using different brands of paper, or using different kinds of paper, such as copperplate, film and special paper); one-sided pursuit of minimizing dot enlargement in proofing results in small white holes in the center of dots. If these deviations occur, the printed products will not catch up with proofing directly. In fact, even if the same set of film is proofed twice, the proofs will be different.
3. color error:
There are three kinds of color errors, the first is the deviation between the color of the printed matter and the proofing; the second is that there is a certain degree of inconsistency between the internal color of the same batch of printed matter before and after; and the third is that there is a deviation between the color of the printed product and the real color itself. The first difference is that we usually say that printing can not catch up with proofing, the reasons have been discussed above, such as ink problems, paper problems, dot reduction problems.
For this difference, the printer should try his best to follow up the sample. If the difference is very big, he should inform the customer in time and sign the sample by the customer himself. The second difference is also an objective problem, and printing machinery itself has been difficult to solve. We know that inking is a dynamic balancing process in the printing process. When the ink on the ink roller is reduced to a certain extent, the printing machine automatically inks to compensate. And the "certain degree" here will directly lead to a batch of printed movable parts in the front of the printed products and the final printed products color deviation. The third difference is actually a psychological expectation problem.
We once met a customer who claimed that the color of the printed product was not exactly the same as that of the physical product itself. We thought that it would damage the company's image and even affect the company's order. However, we thought that the color deviation was acceptable. In this case, it should be said that the deviation is objective and can not be entirely attributed to the quality control of the printing plant. We mentioned earlier that, to be exact, the color of printed products can not be completely consistent with proofing, and there will be ink deviation in the same batch of printed products. Proofing can only be used as a reference standard because it comes out first. Customers may give priority to proofing and think that proofing is good and right.
In this case, we usually consider the color of the product picture first, then the color of other pictures, and finally the decorative color bar or color block. For printing samples for order use, we recommend that customers add a line under the printed matter: "The color in this printed matter is for reference only, and the color is subject to physical object", so as to avoid unnecessary controversy.
4. paper error:
Due to the problems of paper making process, the brightness, thickness and texture of the same kind of paper produced by different paper manufacturers will be different. For example, Zixing, Daewoo and Jindong produced the same gram of copperplate paper, the texture is different, of course, the difference is not too big. For example, Asia-Pacific offset paper, the paper's fineness and whiteness are better than those of other domestic manufacturers, but the price is also about 50% higher.
In addition, the same weight of paper produced by the same manufacturer may change slightly in the production process due to different time of leaving the factory, plus acceptable errors and other reasons, its brightness, thickness and texture are also different. In fact, in the label of each batch of paper purchased by the printing plant, the paper mill has made such a statement in advance, requiring that it should not be mixed with the previous paper in order to avoid deviations in user comparisons. For printing plants, they should provide customers with the printed product pattern to be used before each printing, and then put it into printing after confirmation by customers, so as to avoid such disputes.
5. printing machine error:
The errors of printing machinery are embodied in two points. One is the problem of overprint accuracy, the other is the ink color problem. We know that color printing is actually four-color overprinting, that is, red, yellow, blue and black four-color overlapping together, and the content of overprinting is reflected in the film, which is the point we mentioned earlier, in general, is a small dot.
According to China's printing machinery industry standards, the accuracy of printing press set, that is, the dot overlay accuracy requirement is 0.033 mm, the actual mechanical accuracy is generally higher than this standard, mostly 0.01 mm, of course, some printing machinery is 0.1 mm (mostly monochrome). Even so, if you use a 40-fold magnifying glass to observe the printed products, you can still see that the dot overlap deviates. Therefore, in the process of handover of printed products, we can only reach the point where there is no problem to observe with the naked eye. Unless the printed products are rare products for thousands of years, it is impossible for the printing factory to accept the practice of customers picking out faults with magnifiers.
As for the ink color problem, there are some deviations due to the ink compensation of the inking device, which has been discussed in the previous section and will not be repeated here.
6. cutting size error:
After the printing is finished, the next important step is to use the paper cutter to cut the finished products. When cutting finished products, because of the error of the cutter itself, the error after cutting finished products also exists objectively.
In fact, according to the relevant national standards, in RMB printing products, the error range of cutting size is 0.5 mm, and the error range of Securities printing is 1 mm. That is to say, the size of RMB and negotiable securities is not exactly the same, but its error must fall within a certain range. For general printed matter, the size error of cutting is mostly 2 mm up and down.
7. psychological expectation error:
To be precise, the psychological expectation error should not belong to the category of printing error discussed by us. The reason why we mention this problem is that in the process of dealing with customers, it is a problem we often encounter, which is difficult to solve, but we have to face. For customers who have been exposed to printed matter for a long time, after long-term experience and knowledge accumulation, they have a clear insight into which errors are acceptable and which ones are unacceptable. It is easier to communicate with printing plants.
And some customers may have very high psychological expectations when making printed matter, hoping to make the printed matter beautiful. For this part of customers, printing companies should take on the task of education and training market, and communicate with customers more. After all, printed matter is printed matter, not artwork. Bad communication is an unpleasant memory for both sides.