Design
If I were to think about who the best designer is/was in painting I'd go right for Gustav Klimt. We all know his work, The Kiss, right? Everyone has seen his brilliant figurative works where he somehow bent and recarved the exterior line of a figure without ruining the integrity of the figure itself but I was unfamiliar with his landscapes. At least until I discovered a book dedicated to this topic. Not only was he a tremendous shape maker, he was flat out a great designer of space. His landscapes somehow bridge a decorative form of picture making and abstraction in a most delightful way. His paintings were adventurous explorations into different ways to break up a rectangle and a treatise on the power one note of color can have in a painting. And he did something I don't think anyone else had done to that point, he activated the edges, sometimes making the most important shapes happen in the upper corners of the painting.
If you look at any of his landscapes it would seem that the entire painting was created in order to support one or two small but vital events in the work, a note of purple or a small bright sky hole that breaks through a dark forest of pattern. Using inventive space and lyrical shapes, he gave the simplest tree the same sensuousness he gave his figures. Consider the weight one note can have against a much larger mass of subtle color notes in his work. Look at the rhythm of negative spaces, repeating yet no two are exactly alike. In this piece the entire structure exists to back up the one thin birch in the foreground and mr. birches two bigger mauve cousins. And by the way, Klimt wore a tunic and liked cats. He was cool.