My tutorial title is "Dematerialize watercolors and get an ultra-white background (without variation of shadow and light)"
After lots of different and varied tests (like the disappointing white balance method), I finally found an ideal method (in my opinion) to shoot my watercolors and make the color of paper like a perfect white. The idea is to take two pictures with a fixed camera. We first photograph the watercolor, and then a white sheet of the same size and the same paper lay exactly in the same place. In this way, the second picture can act as a reference to determine the values of the blanks, pixel by pixel. Video tutorial ... is here: