Pressure characteristic
A printing characteristic is the graphic representation of the dot gain (in halftone printing: dot gain) for different printing processes and different printing machines , substrates and inks .
If an image is printed, there will be an increase in dots depending on the substrate, printing machine and printing technology. This increase leads to an increased tone value and thus to a difference between the original image and the printed image . In order to measure this increase, printing characteristics of the printing machine (if necessary of the individual printing units ) are created. For this purpose, test prints are made, the actual area coverage is measured and the results are presented in a table or graphic (see illustration). Based on the determined values, the tonal values of the original (nowadays usually an image file) can be adjusted, i.e. reduced, so that the printed image corresponds to the original in terms of its color values.
development
The creation and use of printing characteristics has declined since the increased use of digital printing plate exposure ( CtP ), as one of the key factors influencing dot gain, printing plate exposure, has been minimized. However, since the influence of the printing press still exists, it is still useful to determine it in the larger print shops for in-house adaptation of the files supplied.