20 Mark

Blaubeuren was a small administrative district in the Kingdom of Württemberg, and this note is a product of the hyperinflationary emergency currency wave — Notgeld — that forced even minor district offices to issue their own paper. The embossed seal was the issuing authority's primary claim to legitimacy, replacing the bank infrastructure that simply didn't exist at this level of local government.

The designer credit "Wlh. Eberbach" almost certainly refers to Wilhelm Eberbach, a locally employed official or commercial artist rather than a professional banknote engraver — district-level Notgeld was routinely designed by whoever was available.