Calibration+ helps you for alternate process printing, by allowing fine tone control on your digital negatives.
For instance, the cyanotype process is contrasted with poor half tones. Calibration+ helps you to have better prints with dark, white and halftones by designing a correction curve.
With Calibration+, generate a reference chart on your device. Use your favorite image processing software :Adobe Photoshop™, Gimp, Affinity Photo™, Lightroom™… to generate digital negative. Invert. Flip. Print (as usual).
Photograph the print! Calibration+ computes the adjustment curve in your photo software to have perfect prints.