Wenschow method

The manual production of a relief model is very expensive, as many hours of manual work is required for each model. Before the invention by Karl Wenschow (1884–1947), a German sculptor and cartographer, each plaster cast had to be painted separately. After World War I, Wenschow developed a method to make pre-printed cartographic maps by using pressing machines.

The contour lines of a cartographic map provided the base for the construction of a matrix by means of a pantograph. Using the die stamping technique, cartographic maps were pressed into form. The paper was made ductile using a substance of unknown composition. Through this procedure, the paper achieved a rubber-like consistency [1]. The substance was not applied uniformly over the whole sheet: The steeper the slope of a certain area the more of the substance was applied. The back side of each sheet of a production run was impregnated with this substance using a template [2]. Then, the negative stamping mould pressed the paper against a ductile mass of artificial wood [3] that strengthened the paper after hardening. The pressing of one model took about 5 to 6 minutes [4].

Wenschow's reliefs were considered as very lightweight, durable and unbreakable. But one restriction is the limited possibility of displaying high steep slopes or high mountain regions, for example of rock faces, because of the limited ductility of the paper.

Wenschow's invention provided relatively cheap terrain models. In principle, it anticipated the method developed in the USA after World War II by using thermoplastic vinyl sheets still in use today.

Most of Wenschow's relief models depict German landscapes, but there also exists a considerable amount of models showing non-native terrains [5]. The predominant scales used were 1:25,000 and 1:200,000 [6].