Seems I was a bit off in my description of Klee’s technique in the previous post. Don’t know where the information comes from, but here is a description from another blog:
“His ‘oil-transfer’ was essentially a home-made tracing system. A sheet of paper coated with black oil paint was, when dry to the touch, laid face down on what would be the host sheet for the image. On top of both was placed a drawing, the lines of which were retraced with an etching needle so as to press the oil paint onto the bottom sheet. The atmosphere of these ‘oil-transfer’ drawings is enhanced by the smudges of black paint pressed through by the drawing hand and which provides a resist to the superimposed coloured washes.”
This kind of thing is fascinating to me. So it was a form of monoprinting, but also resembled something else. Especially interesting is the suggestion that the watercolour was added later. Could have been before and/or after.