I have no idea historically where the idea came from that it is bad to combine white paint with watercolour. As far back as the early 1900’s, famous watercolourists were not at all shy to combine white gouache with their watercolour paintings. I think it is a modern, and in my opinion, misguided practice to teach people that using white paint is ‘cheating’. I get riled up when someone says that. By golly this is art, not brain surgery, and I say – if it works use it! What’s the alternative? You have this beautiful painting and one small area has become too dark. You’ve done all the lifting you can and it’s not going to work. It would be such a waste to throw it out. Why not get out the white paint and fix it? What do you think?