This image is a promotional design for glass painter Ernst Kraus, drawn by Bauhaus graphic artist Herbert Bayer in 1923. It shows a coloured 3D perspective and schematic annotated sideview (rechts) of a roof advertisement (Dachreklame).

Bayer created the design with pencil, ink and gouache (opaque watercolour paint) on paper. The image is not perfect: some assisting sketch lines are still visible, the surface areas are not evenly filled and text letters ‘bleed’ a little. Because of the matte monotonous colouring it is hard to perceive the parts’ material and texture, but I guess it’s metal bars and printed wooden boards. Today, this drawing would not be accepted as production brief, but a full 3D CAD model with complete Bill Of Materials are needed to realise this design.

The bright colours and bold typeface are exemplary for the Bauhaus movement, of which Bayer was a prominent member. In combination with the offset rectangles, they make for a remarkable advertisement sign, that is fitting to the industrial-artistic business of the glass painter. If this design was eventually constructed and placed on a roof in a German town centre, it would definitely have attracted customers’ attention in a striking yet elegant way.

The two perspectives in the image give the viewer an impression of the intended design, but do not offer enough information to perceive all sides of the object and understand how it should be produced and assembled. What are the colours of the other sides of the boards? How does the structure attach to the roof? Fortunately, Bayer did not just deliver this one drawing, but also produced a version with black background and an image from a slightly different perspective, helping the client build the mental model of the object in a real-life context.