With the advancement of human society and economic development, people are using more and more of various image prints. The most important factor in image products, color, is more and more valued by users and designers. In the design and production of image products, proofing is an important means of controlling color. Through proofing, various errors can be avoided. When people mention proofing, they often refer to plate proofing (contract proofing) before printing. Although the contract proofing is the most important proofing in the entire color image product design and production process, it is not the only proofing required in the entire process. In fact, proofing work is required at all stages of the entire design and production process. However, due to the limitations of proofing technology, the importance of proofing in other links has been limited and weakened. It has been ignored by people and the corresponding people (eg designers) have paid a certain price for this.
With the rapid development of computer technology and image printing technology, great changes have taken place in the design and production process of image products, and the matching technology and methods of proofing are also constantly developing. As a world-renowned provider of computing and imaging solutions, Hewlett-Packard has always been an absolute leader in the field of printing. It has a unique ability to predict and analyze the market. It is good at discovering the market, good at understanding user needs, and good at constantly Market Demand The most suitable printing products and solutions for users are introduced.
Image products need to be designed for proofing. In the design and production of image products, users, designers, plate-making centers, and printing factory personnel are involved. They compose the design and production process of the entire image product. In order to obtain better image products, they are most concerned about two proofs throughout the entire design and production process: design proofing for designers, and platemaking for contracting centers (contract proofing).
The most important part of an image product is color. Designers mainly rely on color to express their unique ideas on the final image product. Even if the designer has a good design idea, but if it can not be fully and accurately shown in the final product, then this design still can not be recognized by the user, and then even affect the user's trust in the designer, and follow-up business .
For designers, they need to design proofing to help them design, not only for designers to communicate and communicate with each other, but more importantly to present their various design ideas to the user in a true and complete manner, and to the later stage. The printing production provides a reference. So what are the requirements for design proofing?
The test of color. Since designers are now designing on a computer, they are represented on the screen in RGB, and the final product is printed in CMYK. Since the gamut spaces of RGB and CMYK are different, it is highly likely that the printed colors will be different from the designer's desired colors (the colors seen on the screen). To prevent this from happening, designers need proofing to mimic printed color effects to help them design.
Test the text content. Because image products include not only color, but also text, lines, and other content, and with the power of various image design software, people can carry out more and more complex design on the computer, then it is even more necessary to design and print to help designers. Inspection to prevent the occurrence of various errors.
Improve the design project bidding effect chart. Designing bids is an extremely important means for designers to express their design ideas to customers. The failure of design thinking can lead to failure in tendering; if the customer approves the design idea of ​​the designer, it cannot be realized in the subsequent printing production process, and it will inevitably bring irreparable damage to the designer.
Now due to price factors, designers generally use A3 format inkjet printers for general office proofing. However, due to the limitation of the performance of ordinary inkjet printers, designers can only use it to complete the inspection of the text content, and the inspection of the color printing effect cannot be achieved. This can only be done with late-stage proofing (contract proofing). This will inevitably bring about various inevitable problems. E.g:
The growth of the design cycle: Because the designer can not see the future printing effect at the same time of the design, the color can only be designed based on experience. The designer can only find out the plate-making proof provided by the plate-making center before it can be found. modify. And now the time that the platemaking center needs to provide plate proofing is at least half a day. Once a deviation occurs, the entire design cycle will be extended. Previously, users have been able to accept the growth of this design cycle, and now it has become increasingly impossible. Due to the accelerated pace of work and fierce competition in the market, the design time for the designer to the designer is getting shorter and shorter. Often, the customer confirms the contents of the color, text, etc. at the last minute. Once design deviations occur, it is difficult for designers to catch up in time.
The increase in production costs and the increase in costs: As the majority of domestic plate-making centers improve the proofing of the plate-making process, they are all first to produce a film and then proof. Once a design problem is found in the proofing, the designer not only has to pay multiple proofing fees, but also has to pay multiple fees for the film. In today's increasingly fierce competition, the increase in costs will inevitably reduce the designer's competitiveness, and will eventually be eliminated by the industry.
There is no ideal bid effect: If the designer adopts an ordinary office inkjet printer for proofing, it must be unable to provide high-quality design results to the client. Therefore, in the bidding process of the client's project, it is inevitable that it will be difficult to obtain in the tender. victory.
Plate-making proofing is a very important process in the prepress process. It is provided by the plate-making center to the designers and users. It is a powerful means to control the quality of the printed matter (mainly color quality) and is used to check the plate-making film. A means of quality, and for the user to confirm, sign the use (that is, the contract signed).
Regardless of whether it is for design proofing or pattern proofing, the proofing method that is commonly used today is the offset proofing machine (called traditional proofing). However, it has unstable proofing quality, high modification cost, long cycle, large investment, and land occupation. Large space, not suitable for the development of printing new technologies and other shortcomings. Therefore, the plate printing industry is always looking for new proofing methods instead of traditional proofing.
The new proofing method can not reach people's requirement for color proofing because of the output effect of the ordinary A3 format office inkjet printer used by designers. People often do not call it proofing. The traditional offset printing and proofing methods also have many problems that cannot be overcome. Therefore, people are always trying to find new proofing methods to improve the entire design, plate making, and printing production processes. People have also discovered several different proofing methods (for example, laser proofing or Overlay proofing with optical or chemical proofing) for several decades. However, due to some insurmountable reasons (such as: the expense is still high, still after the first filming Proofing, etc., cannot replace the offset plate proofing, making it more difficult to get into the designer's line of sight.
In the past few years, a new proofing method has entered the field of vision - digital proofing using inkjet printing technology and with the development of inkjet printing technology, more and more people recognized.
Digital proofing color effect: Digital proofing system has generally adopted 6 color ink system and precise ink drop control technology (such as: HP's color layering technology), so that the color space is larger than the color space of the printing proofing, and its color effect Can completely imitate the color effect of the traditional proofing, to meet the user's requirements for color proofing.
Digital proofing quality is stable and works in a normal office environment. Like the HP Designjet 5000 large format printer, it is equipped with a temperature and humidity sensor. When the temperature and humidity changes, it can be automatically adjusted to ensure the stability of the print quality.
Digital proofing quality is stable and is not affected by human factors: due to the use of digital technology, once the proofing and grading file (ICC file) is determined, the proofing color of each figure is determined, regardless of the level of the operator, and only the operator presses. Related steps can be operated.
Reduce the cost of modification and speed up the cycle: Because the digital proofing is the first proofing, after the film, so once the proofing effect can not meet the requirements of the customer, the plate-making company must be modified, then only need to proof again, until the customer satisfaction, signature confirmation, without much Repeatedly out of the film, to avoid unnecessary waste and increase costs.
Small investment: The initial investment of the digital proofing system is only a few hundred thousand (computers, large format printers and related software).
Occupies a small space: only a dozen square meters, and can be run in an ordinary office environment, to avoid the greater investment in the plant.
Adapt to the development of new printing technologies: It is easy to cooperate with CTP (computer-to-plate) and digital printing machines and other digital devices to meet the needs of new technology development.
Since ink jet printing technology is adopted, what is the difference between digital proofing equipment and A3 format printers commonly used by current designers? Is it just a six-ink system with a resolution of 1200dpi or 2400dpi? This is not the case. The above conditions are only necessary for the digital proofing system. Only with these conditions can not meet people's requirements for proofing equipment, especially the performance of the printing requirements, proofing equipment must also be equipped with a corresponding color management system (professional proofing software).
Three steps of color management Because the processing methods for different colors between different devices (scanners, monitors, printers, and printers) are different, the color space in each color space is different, so the color mismatch phenomenon will inevitably occur. For any device, there must be some color outside its color gamut.
Ideally, color should maintain color stability and predictability throughout the design and printing process. However, this requirement for color cannot be achieved naturally, and the color management system (CMS) can overcome this problem to help people achieve the desired color stability and predictability. CMS manages the gamut space of different devices in the workflow, converts scanned RGB color data to CMYK data, and also converts CMYK data to CMYK values ​​for different output devices for color proofing or actual printing.
The basis of color management is to ensure that all devices are in the color reproduction system. To achieve the goal of color management, we must go through three color management steps: device calibration, characterization calibration, and color gamut conversion:
Equipment Calibration: Some people think that the term "equipment calibration" refers to all the steps to get accurate color, perhaps meaning that the copied color is calibrated to match the original color. But in fact, calibration equipment is just one of three steps in color management. Device calibration itself does not guarantee color matching. It only calibrates the performance of the device itself. It can only ensure that the device (such as scanners, monitors, printers) meets its specified specifications and provides a way to ensure that it is Stable work for a period of time.
Profiling: A method of measuring and quantifying the color space, color gamut, and color characteristics of a particular device under known circumstances. It is used to determine how to acquire color or record color when an input device or an output device is calibrated. Characterization calibration is the process of actually creating your device description file for scanners, monitors, printers, and more. To achieve characterization calibration requires the device itself to be equipped with a high-performance color sensor, with which color management software can be used in order to implement a true characterization calibration; otherwise these devices must rely on a separate calibration device (such as a color tone meter) , In conjunction with color management software, characteristic calibration can be implemented.
Color gamut conversion (color transfer): This is the process of converting image colors from one device's gamut data to another device's gamut data. Through color management software (commonly known as RIP software), color gamut conversion can be achieved manually or automatically. Switching between the gamuts of different devices is often referred to as gamut mapping.
How to choose the proofing system of digital proofing system The proofing system using ink jet printing technology (referred to as the digital proofing system) has been changed