Time and again there are unexplainable visual color deviations between proof and print because the digital proof production process does not correspond to offset printing technology: for instance no screen dots, other color pigments, every tone value step may change independently from the one either side of it. Proof Zebrastrip® takes this into account and permits optimal proof rating based on Eurostandard System Brunner.
Whereas in an analog environment only a few tone value steps (25%, 50%, 75%) might have been enough to sufficiently characterize a transfer characteristic curve, this is definitely not enough for digital technology. Therefore the Zebrastrip® measuring patch sequence in the professional version has 20 measuring points, and they are selected to conditions, when the standard characteristic curve is maintained, the same area coverage differences appear.
The new Proof Zebrastrip® contains the Zebrastrip gray balance along with Zebrastrips for all primary colors and the secondary colors in an abbreviated version. A special feature of Proof Zebrastrip® are the gray stabilization patches that lie in the gray area and are made up of four colors with a high black proportion. Whereas these stabilized gray tones cause hardly any difficulties in the printing process, they are harder to achieve with digital proofs depending on the RIP and inkjet technology. The measuring element also has color patches that represent skin tones, tertiary tones and saturated hues.
The Proof Checker System Brunner® software can measure every proof in a few seconds, check its conformity with the print standard, and easily rate it with the aid of stars. In doing this the software evaluates and weights 50 process-related and colorimetrical parameters that influence the color of the proof. The metrological evaluation is done using customary spectral measurement scanning devices.
Proof Zebrastrip Versions A and B
Due to the compact dimensions, Proof Zebrastrip v1.0-A and -B are suitable for checking proofs as well as production runs. With the aid of 20 screen steps the characteristic curves of the primary colors of the proof or the print and also gray balance homogeneity can be ascertained. Evaluation can be done with the Techkon RS 800 in either scanning or spot measurement mode.
Proof Zebrastrip Version C
Because of its larger measuring patches, the Proof Zebrastrip v1.0-C is mainly intended for checking digital proofs and has 10 instead of 20 screen steps for the primary colors. Evaluation can be done with the Xrite/GretagMacbeth EyeOne device in either scanning or spot measurement mode.