Thanks! Yes, I have watched few videos from Mark and his Carder's method is really strong, I love his approach to painting. Concerning Ultramarine: the goal was to reach strong warm/cool contrast with Zorn's palette, with focus on skintones. When I use Ultramarine blue in limited palette I would take Transparent Red Oxide as my yellow, Alizarin as my red and Ultramarine as blue which would be strongest color. And it's good exercise when you try to mix color you don't have )