PressCal Press Forms / 2020-05-16

This folder contains InDesign documents meant as a starting point for your calibration test form. The entire press sheet has a gray background of alternating black and CMY stripes. PressCal test charts are located in the center, oriented so the tone ramps wrap around the press cylinder. There are several different PressCal test charts, described below. Charts have been created for X-Rite i1iO 2, i1iO 3 and i1iSis instruments. If you have a different instrument, you may create your own chart from the reference files provided in the test chart package, http://optimalmethod.org/resources/PressCal_test_charts.zip

You should modify these test forms for your own use by cropping the background for your press and paper configuration, and placing your normal control strips. Feel free to add your own test images in the areas to the left and right of the PressCal test charts.

There are three basic test charts – PressCalF51, PressCalC6, and PressCalP. Transposed versions of these test charts have an 'T' in the name – PressCalF51T, PressCalC6T, and PressCalPT. If the samples are shuffled, there is an 'S' in the name – PressCalF51TS, PressCalC6TS, and PressCalPTS.

The first 5 rows of the PressCalPT chart contain tone ramps for C, M, Y, K and CMY gray. The remaining rows (6 - 25) contain a characterization test chart, designed for profiling an offset press. This small chart is a subset of the IT8.7/4 test chart. By combining these elements into a single chart, it is possible to make TVI-based curves, gray-based (TR-015) curves, OPTIMAL curves, and ICC profiles, all from the same measurement data.

The first 5 rows of the PressCalC6T chart are the same as the PressCalPT chart. The remaining rows (6 - 20) are a 25-step CMYK gray axis ramp and a 7 x 7 x 7 array of samples derived from the GRACoL2013_CRPC6.icc reference profile. This chart is designed to make degree 6 optimal curves. It cannot be used to make ICC profiles.

The PressCalF51T charts are the same as the PressCalC6T charts, except rows (6 - 20) were derived from the PSOcoated_v3.icc reference profile. This profile is based on the FOGRA51 data set, commonly used in Europe.

The PressCalPTS, PressCalC6TS, and PressCalF51TS charts are the same as PressCalPT, PressCalC6T, and PressCalF51T except rows 7 and up are shuffled (randomized).

