Digital Printing Artwork High-simulation Duplicated Color Management

In recent years, many well-known museums at home and abroad have been working on the reproduction of works of art and have limited sales. They are favored by artists, collectors and art lovers. For example, the Beijing National Palace Museum, the Metropolitan Museum of Art in New York, the Louvre Museum in Paris, France, and the British Museum in London in the United Kingdom all used Epson Stylus Pro series large format inkjet printers to reproduce artworks, making many works of art very realistic. Realistic, it can almost be real.

The use of digital printing technology for high-fidelity reproduction of art can not be separated from the color management, color management is the key and the core of high-simulation replication. Modern color management is a color control technology whose core is the change of color space. It realizes vivid color reproduction through color space conversion.

First, create a high-simulation copy color management system

In the reproduction of works of art, color is an important carrier for the transmission of artistic information. It embodies or reflects the “connotation” of the works. Its focus is on reproducing the colors of the artworks realistically on coated rice paper, silk and canvas. Then, the emergence of the current ICC color management and art micro-jet printing, for the accurate transmission and control of modern colors, provides a new way for high-fidelity reproduction of artworks.

Color management refers to the management of the transfer of color space (such as scanners, monitors, inkjet printers). Color management requires the color information to be as consistent as possible in the three processes of input, processing, and output. However, the colors involved in the process of transmission involve hardware and software that are not exactly the same. Therefore, to maintain consistency and stability in the process of color information delivery, standardized color management must be implemented.

Beijing Shenghong Rainbow has applied digital technology creatively for many years and established a color management system with its own characteristics. It has a high reputation in the industry. The company has an independent digital color technology research and development center and carries out research and practice of color management standardization.

In recent years, research and development of digital printing high-simulation copying technology is the use of self-developed new materials (with coated rice paper, silk and canvas) + new technology (Epson Stylus Pro 9800 inkjet printer) + new software ( GMG Color Proof color management software), and create a color management data integration module featuring the company's characteristics, and conduct high-simulation copying of color management, so that the quality of art reproduction is improved to a new level. His copy of the "Forbidden Museum Collection of Painting and Calligraphy" and "Liaoning Museum of the Qing Dynasty paintings and paintings and simulative products" series of products, not only to achieve "like shape", the ink Yun dry, wet, thick, light show properly, color configuration and ancient painting color matching Correspondingly, the texture of rice paper, silk and canvas is the same as that of a real canvas, and it achieves “likeness” and maintains the original charm of the original. It embodies and reflects the “connotation” of the work and embodies the perfect combination of art and technology. Called "printed artwork."

Color management is the technological core of Shengcaihong. Its characteristic is that it is not simply applied to local equipment such as ink jet printers. Instead, it creates the “Sheng Caihong artwork high-simulation copying color management system” and fully realizes the calibration of the equipment. Color profile, and integrate the software and hardware matching of color conversion between multiple devices into a complete system throughout the entire process. The entire workflow is controlled by digital technology, and the process flow is closely connected to ensure the color information of the entire link. The loss is small, so as to achieve a faithful reproduction of the original works quickly and well.

The color management of the entire digital workflow goes through 4 steps:
1. RGB color management of digital scanners;
2. RGB color management in Photoshop;
3. CMYK color management for inkjet printers;
4. CMYK color management in Photoshop.
Among them, 2nd and 4th color management are used in the image conversion format

Second, high simulation copy color management methods and steps

(A) Scanner color management

One of the key links in the high-fidelity reproduction of works of art is to use the original for physical scanning, and to obtain all the information needed from the original during scanning. Saint-Rainen uses a large format digital physical scanner from the company Cruse, Germany. Its maximum size is 1.8m x 1m, and the highest precision is 470dpi. It can scan original color information in detail and provide high-definition scanned images for art reproduction. The document thus reduces the loss of the color information that is caused by the conventional reproduction of the original document by the original document and scanning with the secondary document.

1. Scanner calibration

First, the scanner is calibrated to the best working condition, and the scanning light source, mirror, and analog converter are calibrated to correctly reproduce the original color information and gray balance. The digital physical scanner uses RGB three-color filters to separate the original color, and then reaches the CCD optocoupler to become independent RGB image information. Therefore, you must fine-tune the balance between white field, middle tone, and black field.

Scanner In the RGB format, from the theory of color mixing, the RGB light is mixed with the same amount to become gray (Table 1).

Table 1
White gray light gray gray dark gray
R 255 191 127 64 0
G 255 191 127 64 0
B 255 191 127 64 0

2. Formal scan. Standard scans were performed using the HCT/IT8 reflection color scale.
3. Use the scanned HCT/IT8 color scale to generate the scanner's RGB ICC in the Profile Maker software.
4. Install the scanner's ICC file in the computer's system folder.
5. After the installation, you can see the ICC file in the Photoshop software, and you can configure the ICC file for the scanned picture.
Through the original data, directly use the ICC data to edit the ICC data adjustment, to achieve the same amount of RGB three-color channel (as shown in Figure 1).
6. The color gamut represented by the RGB color mode is larger than the color gamut of the CMYK mode. This is the basis for high-fidelity reproduction of the artworks. After undergoing rigorous digital testing in the laboratory, and through several improvements in production practices, the CIELab color space measurement model was printed using a simulation material (rice paper and silk file) + inkjet printer (Century "Iris K3" eight-color pigment ink). (as shown in picture 2).
7. Finally set the CMYK ICC file for the device based on the final output device.
When generating the CMYK ICC file for the output device and simulation material, a GCR long blacktone process that conforms to Chinese painting characteristics is used. The setting K is 0-100%, the maximum point of the CMYK color is set to 80%, and the total ink amount is 340 %, the darkest version is 100%, and the black version replaces the color range by 50%.
8. Based on the above-mentioned standardization of scans, Photoshop software is used again to perform meticulous technical processing and art processing to faithfully reproduce the original ink rhyme and color.
9. After the above steps are completed, the color difference between the screen color and the “art micro spray” printing coated rice paper is close. In this state, the color management software is used to edit and modify the ICC into the final CMM module data, so that the screen color is basically the same as the coated rice paper and the ink color.

(b) Display color management

Choosing a good quality display and building a display profile is an important part of the high-simulation reproduction color management. Since the color of the display is unlikely to achieve the desired effect, in the RGB tri-color emitters, color cast occurs if there is only a slight imbalance. Therefore, it is necessary to use a precision measuring instrument to measure the RGB of the display screen, and accurately input the color light coordinates or perform hardware adjustment on the three-color emitter.

1. Use EIZO FLE×SCANL CG 21 inch LCD monitor and Apple 23 inch monitor.
2. Use a professional spectrophotometer and professional measurement software to calibrate the display. The calibration includes 5500°K color temperature, contrast (0 to 100), and gamma (2.2) for the monitor.
3. In the Photoshop screen soft proofing.

(1) After calibration of the above-mentioned display itself, the ICC file of the display is generated and copied to the Profile in the system folder.
(2) In the "Color Settings" dialog box in Photoshop, place the ICC file corresponding to the color value of the previously manufactured coated rice paper or coated silk 1485 color block.

(C) establish a standard color environment

For high-simulation copy color management, a standard ambient light source should be used to keep the indoor light constant, so that the original color of the artwork is basically the same as the screen color and the printing color of the coated rice paper.

The core components of the standard light source are: First, a good color temperature. The company uses ISO3664:2000, an international standard for the viewing conditions of image technology and photography industry standards. It recommends that the basic observation lighting be correlated with the correlated color temperature at 5000°. K's daylight spectral distribution matches the CIED50 standardized light source. The second is a fluorescent lamp with a higher display index, R value should be greater than 95% of the spectral display characteristics, the company's specifications using the German JUST's fluorescent tubes, display index of 97%, can completely reflect the true color of the illuminated object.

Third , the art micro-jet printing color management

For high-fidelity copying of digitally-printed artworks, the printed product is a finished product directly, and the demand vividly reproduces the tonality of the original, rather than commercial printing to simulate the printing effect. Therefore, careful color management of art micro-jet printing is the key. Saint-Rainco uses Epson Stylus Pro 9800 inkjet printer + GMG color management software + self-developed coated rice paper, silk and canvas to form color management of the entire system. .

1. Elaborately establish an ICC document for art micro-jet printing.

The art micro-jet printing quality is closely related to the quality of professional color management software, inkjet printers, pigment inks, and coated rice paper. Therefore, establishing an ICC document that is suitable for art micro-jet printing is the most important aspect of high-fidelity replication, and the best system matching must be achieved.

(1) Matching of color management equipment

1 Use Epson Stylus Pro 9800. One is to use its advantages of FM network, its 1440dpi FM network can not use 10 times magnifier network outlets, color level transition is natural and soft, continuous good printing effect. The second is the use of its "Century Iris K3" ink, printing products with accurate color, wide color gamut, its three-color black and Chinese painting ink match, in particular, which the matte black density of up to 2.3, can show black and white printing on rice paper The concentration is suitable for the color reproduction of high-simulation artworks.

2 Select new materials developed independently. The company developed a polymer polymeric coating material that meets the needs of the art micro-jet printing, and uses nanotechnology to achieve the best granularity of the coating, achieving a higher contrast between the coated rice paper, silk and canvas, and a higher color gamut. Wide, more saturated colors.

3 Use more color samples. How much of the color patch is sampled determines the accuracy of the color. Therefore, the company selected ECI 2002V color standard, a total of 1485 color blocks, the color standard printing in the original inch.

4 Select the feature file generation software. Color profiles play an important role. Therefore, profile software becomes the key and foundation for color management. Select GretagMacbeth Profile Maker color profile generation software.

5 Select the spectrophotometer. The most accurate method of color description is spectral data. To obtain spectral data, a spectrophotometer should be used to measure 1,485 color patches in the ECI 2002V color scale produced by the output device for the chromaticity values ​​L, a, and b. After the results are compared with the standard data, new spectral information is obtained and the ICC file of the output device is established. The company selected the GretagMacbeth Spectromatt spectrophotometer, which can accurately measure spectral data. At the same time, it can calibrate the measurement instrument when it is used. The distance between the cursor and the paper is about 2mm.

(2) Fundamental Linearization of Inkjet Printers

The basic linearization determines the physical properties under the combined action of the pigment inks coated with rice paper, silk rayon, and canvas, and optimizes the total ink ejection volume and single channel ink volume of the inkjet printer. That is, using the best amount of ink to obtain the largest possible color density provides the basis and optimization characteristics for the creation of artistic microjet printing and coating rice paper and silk ICC files, thereby establishing the basis for color management.

The linearization of ink jet printers is based on the principle of correcting deviations in the printed colors by checking and adjusting the density of the microjets. Therefore, first adjust the micro-injector to the most stable working condition.

The film has excellent heat sealing performance and excellent transparency, is one of the main packaging composite base materials, used in the production of high-temperature boiling film, vacuum aluminum coating film, the market is very optimistic.Moreover, with the development of domestic production equipment, some of the technical indicators have reached the international advanced level.As a result, the threshold to enter the film production is lower and lower.Because of this, some enterprises rush to import the flow of film production line in order to reach the designated position, the higher the level, the better, while leaving the market demand and the return on investment aside, which will cause huge waste of resources.

Viscose Coated PE Film With Glue

Viscose Coated PE Film With Glue,High Density Polyethylene Glue,Polyethylene Adhesive,Waterproof Polyethylene Glue,Ultrasoft Lamination