Hold up the hope of design proofing 2

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 Hewlett-Packard DESigNJET5000 large-format printer, because of its own temperature and humidity sensors, when the temperature and humidity have changed, they 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 adopting digital technology, once the proofing and coloring document (TCC file) is determined, the proofing color of each figure is determined, regardless of the operator's level, 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 software, so once the proofing effect can not meet the customer's request, 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 can easily cooperate with digital devices such as CTP (computer-to-plate) and digital printers to meet the needs of new technology development.
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).
Third, the three steps of color management Because different devices (scanners, monitors, printers, printers) deal with the different colors, the color space of their own will be different, it is bound to appear color mismatch phenomenon. 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.
For 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. However, in fact, calibration equipment is only one of the three steps of color management. The calibration itself does not guarantee the matching of colors. It only calibrates the performance of the equipment itself and only guarantees the equipment (eg scanners, monitors, printers). Reaching its prescribed index provides a way to ensure that it will work stably for a period of time.
Characterization calibration (PRoFiliNg) is 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 achieved.
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 RTP software), color gamut conversion can be achieved manually or automatically. Switching between the gamuts of different devices is often referred to as gamut mapping.
Fourth, how to choose the digital proofing system Inkjet printing technology proofing system (referred to as digital proofing system) has been more and more used in design proofing and prepress plate proofing, then choose a digital proofing system should consider what factors?
1. Color Accuracy Color accuracy is the accuracy of matching with the target color. To make comparison easier, people now quantify it by choosing a suitable target color gamut and then measuring its deviation through a color management system. People use dE to indicate this deviation. A good digital proofing system should have a dE between 3 and 5. Here are the color effects of dE in different ranges:
1.6 to 3.2 viewed from a distance, basically do not see the difference in color. This is usually considered to be the same color. The color difference of 3.2 to 6.5 is visible, but the color gives the impression that people are basically the same;
The difference of 6.5-1.3 colors can be seen, but it can be considered as the same color tone;
13 to 25 are considered different shades. Above this value, it is considered a different color. (to be continued)