“…In fact, once it is realized that both visual space and pictorial space are not strictly Euclidean spaces, because they are dimensional, coloured, textured, expressive, crossmodal and inherently dependent on the perception of the beholder, the question arises as what primitives, characteristics, and laws regulate their organization. From this point of view, Klee's pictorial work is a kind of 'laboratory' for the identification and construction of a genetic geometry of visual appearances (Albertazzi, 2013). The idea that as soon as a line is drawn, be it angular, continuous, chromatic or achromatic, a surface potentially develops (an idea already put forward in Alberti's De Pictura) was subject to study in all Klee's works (see, for example, Raumbildung durch Bewegte Gerade 1931) (Bätschmann 2002).…”