Before doing the G7 certification, all matters need to be prepared accordingly. The following will introduce you to the matters that need to be paid attention to in the preparation stage for time, paper, ink and tools.
Note: As long as the correct materials and test standards are selected, G7 can be applied to any printing process. The following description is for commercial printing calibration of high-quality coated paper. If calibrating other processes, such as SWOP or proofing system, please replace the appropriate raw materials and chroma target values.
time
The entire printing calibration process requires two printing presses, each of which needs to run for one hour to two hours. There is a short break during plate correction (about half an hour to one hour). All running operations need to be scheduled on the same day. On the basis of the same equipment and the same group of operators. Experienced staff can reduce the calibration of the post-process to a process without the second step of "high quality" and "characterization" process.
Paper
According to the efficiency of operation, about 60 to 100 million sheets are required. For commercial printing, try to use ISO 1 type paper without fluorescence. The standard white point is 95L * (± 3), 0a * (± 2), -2b * (± 2) (measured against a white background). For other types of printing methods, please select the appropriate paper in the ISO 12647-2 specification.
ink
Like most printing specifications, the G7 precisely defines the ink color according to the 2846-1 standard. However, in practice, during the entire calibration process where the ink is printed on the actual substrate, the measured standard needs to be as far as possible in accordance with ISO12647-2 Measure the ink at the corresponding ink value of the corresponding paper type in.
Commercial printing ink color
The best solid ink value of ISO1, 2 grade paper:
Note: These values ​​are measured on the basis of no background, and the sample is printed on the material close to the CIELab value (L * 98, a * 0, b * 0)
Test target and image
The pre-configured G7 test samples can be obtained from http: //, or you can make your own.
Tools required for the chart method:
Chart paper: G7 K curve chart paper and G7 CMY curve chart paper
Portable calculator: used to calculate the grayscale target value
Portable spectrodensitometer: used to measure P2P charts and GrayFinder charts
Tools required by the software method:
Curve calculation software: IDEAlink â„¢ Curve: http: //
Software for automatic measurement of P2P target value:
GretagMacbeth: http: //
X-Rite ColorPort: http: //
Dot measuring instrument: a visual printing plate measuring instrument
D-50 Observation light source: a D50 lamp holder or a light source conforming to ISO 3664
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