Soft proofing is a technology also used by Adobe software; it's based on device ICC profiles and, in some cases, standard color spaces. It simulates the printed result on a monitor , as opposed to a paper proof, which is obtained using a printer.

Its main function is to simulate the colors achievable by the printer through the monitor's ICC profile . In other words, when we view an image on a monitor calibrated to specific parameters, what we see is not what we will get in print, but only the representation of the digital image from its source profile to that of the monitor. This display tells us nothing about the colors we could achieve with a specific printer. This is why a monitor color proof is needed.

To obtain a true simulation of the printed result, it is recommended to calibrate your monitor according to these specifications before activating soft-proofing in Photoshop:

White point = between 5800K and 6500K

Gamma = 2.2 or L* (if available)

Luminance = between 80 cd/m2 and 90 cd/m2