The sample before the most popular printing determ

2022-07-27
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Prepress proofs determine print quality

prepress proofing types and advantages and disadvantages

proofs are the weight basis for print quality control and a tool for communication with customers. Their functions are mainly reflected in the following two aspects

first, the sample sheet can help users check various information contained in the document for timely modification, such as font, image, color and page settings. Color is the most difficult to control in proofing, because different substrate materials, inks and dot gain rate will cause the change of sample color

second, the sample can be used as a contract between the customer and the printing factory. The contract sample shall be accurately provided with the same color as the final printed matter, and it is best to print the contract sample shortly before printing to avoid fading and distortion of the sample due to long storage time

proofing is a process connecting prepress production and printing, allowing users to foresee the final print effect before printing. At present, there are three kinds of proofing methods commonly used in gravure printing industry: soft proofing, traditional proofing and digital proofing

1. Soft proofing

soft proofing is realized on the color display. It is undoubtedly the most convenient, fastest and cheapest proofing method. It requires that the color display has high precision and must be calibrated correctly. The obvious disadvantages of soft proofing are: low resolution, only 72dpi; The accuracy of color depends on the performance and calibration of the display; It is not possible to provide reference hard copies for subsequent printing processes

second, traditional proofing

there are two common traditional gravure proofing methods. One is gravure proofing. The color of the obtained sample is accurate and highly referential. However, this proofing method needs to go through processes such as grinding, engraving and electroplating. It requires high processing accuracy of the plate cylinder, high electroplating cost and complex process. Therefore, this proofing method has high production cost, long cycle and takes at least one day

the other method is offset proofing. You need to output the film and print, and then finish proofing on the offset proofing machine. Although this method can reduce part of the production cost, due to the different offset and gravure printing processes, there are great differences in proofing effects, such as insufficient density and equal color levels

the advantages of traditional proofing mainly include the following points

1, the production process of proofing plate and printing plate is similar

2, the same raster data is used for proofing and printing. Potential problems can be found through proofing, such as the tortoise is a kind of auxiliary motor indirect speed change device, and problems such as texture, layout and font

3, good performance in trapping and ink opacity when proofing spot color and metal color

the disadvantages of traditional proofing mainly include the following points:

1, high technical content, professional technicians are required to obtain accurate proofs, and the labor intensity is large

2, higher investment is required

3, involving many processes, high cost and long treatment cycle

third, digital proofing

digital proofing technology is completely controlled by digitization, which changes the previous complex printing production process and reduces the cost. And the stability of plate making and printing quality is greatly improved. In gravure plate making, which does not need to use film, digital proofing is a more appropriate proofing method

the digital proofing technology is very mature and can fully meet the needs of gravure plate making. Most of the design elements in gravure plate making are graphics and images, and more spot colors are used. This is mainly because the colors shown by spot colors are more uniform, more colorful and stable than multi-color overprint. The use of spot colors in anti white graphics or text can reduce the difficulty of registration. Therefore, it is the key to evaluate the quality of gravure digital proofing and test the accuracy of spot color restoration by proofing system. The digital proofing technology can not only meet the current popular general four-color proofing of graphene, but also improve the support ability for spot color. For example, the professional digital proofing system can provide a good solution to the problems often encountered in gravure printing processes, such as spot color overprint and trapping, spot color transparency control, spot color level transition, etc

the advantages of digital proofing mainly include the following points:

1, there is no need to output film or make a plate cylinder. While shortening the connection of production cycle, the screws at all places need to be tightened, the cost can be reduced

2, the quality of samples made based on inkjet technology is usually more stable

3, digital proofing is an important part of digital printing. Its unique stability can provide a standard for the whole printing process and a strong guarantee for the improvement of printing quality

the main disadvantages of digital proofing are as follows:

1. Some digital proofing systems cannot ensure the integrity of document data

2, the digital proofing system with the function of processing eye adjustment needs a higher cost

3, spot color and gold are used to solve the employment problem and improve the competitiveness of products. The color cannot be accurately reproduced, and a specific system must be used

undoubtedly, with the continuous development and improvement of color management technology, digital proofing will show greater advantages in the printing process and occupy a dominant position

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