Calibrating, Printing and Proofing by the G7™ Method

Calibrating, Printing and Proofing by the G7 Method Version 6, August 2006
6 Calibration Test .................................................................................................... 21
6.1 Ink sequence, drying, and coating ....................................................................................................................... 21
6.2 Print to nominal solid ink values........................................................................................................................... 21
6.3 Check CMYK TVI.................................................................................................................................................. 21
6.4 Adjust device-level gray balance (optional)......................................................................................................... 22
6.5 Adjust cross-sheet evenness ............................................................................................................................... 22
6.6 Run stabilizing speed-cycle.................................................................................................................................. 22
6.7 Automated press control systems........................................................................................................................ 23
6.8 Record wet and dry ink values............................................................................................................................. 23
7 Adjusting NPDC Curves ........................................................................................ 24
7.1 Allow sample sheets to dry................................................................................................................................... 24
7.2 Measure the P2P target........................................................................................................................................ 24
7.3 Plot the curves ...................................................................................................................................................... 24
7.4 Find nearest target graph with same D-max ....................................................................................................... 25
7.5 Choose the optimum curve points ....................................................................................................................... 25
7.6 Calculate the RIP curve correction values .......................................................................................................... 25
7.7 Correcting gray balance in RIP curves ................................................................................................................ 26
7.8 Apply new aim values to RIP or CtP device........................................................................................................ 26
8 Achieving Gray Balance in RIP Curves................................................................. 27
8.1 Find the 'most neutral' patch in the C = 50% block............................................................................................. 27
8.2 Repeat for other cyan percentages ..................................................................................................................... 27
8.3 Draw new curves for Magenta and Yellow .......................................................................................................... 28
8.4 Find new aim values for Cyan, Magenta and Yellow.......................................................................................... 28
8.5 Correcting Gray Balance in IDEAlink Curve........................................................................................................ 29
8.6 Apply new aim values to RIP or CtP device........................................................................................................ 29
8.7 When NOT to apply gray balance in RIP curves ................................................................................................ 29
9 Verification/Characterization Test ....................................................................... 30
9.1 Make new characterization plates to G7 spec .................................................................................................... 30
9.2 Print the characterization target ........................................................................................................................... 30
9.3 Characterization tolerances.................................................................................................................................. 30
9.4 Confirm goal curves.............................................................................................................................................. 30
9.5 Verify gray balance and other parameters .......................................................................................................... 31
9.6 Select samples...................................................................................................................................................... 31
9.7 Measure characterization data............................................................................................................................. 31
9.8 Realistic expectations........................................................................................................................................... 31
10 Proofer Calibration and Profiling ........................................................................ 32
10.1 What proofers are compatible with G7? ............................................................................................................ 32
10.2 Workflow summary ............................................................................................................................................. 32
10.3 Qualify the proofing system................................................................................................................................ 32
10.4 Optimize the proofing system ............................................................................................................................ 32
10.5 Print the proofing form target ............................................................................................................................. 33
10.6 Measure the Press2Proof (P2P) target ............................................................................................................. 33
10.7 Plot the curves .................................................................................................................................................... 33
10.8 Align end-points at 100% ................................................................................................................................... 33
10.9 Choose the optimum curve points ..................................................................................................................... 33
10.10 Calculate the RIP curve correction values ...................................................................................................... 33
10.11 Evaluate and adjust gray balance.................................................................................................................... 33
10.12 Apply new aim values to RIP ........................................................................................................................... 33
10.13 Evaluate accuracy in neutral gray areas ......................................................................................................... 34
10.14 Evaluate match in colored areas ..................................................................................................................... 34
10.15 Solve remaining color errors via ICC profiles (if needed)............................................................................... 34
10.16 Testing ICC profiles before installing in a RIP ................................................................................................ 34
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