500 000 Mark

Boppard, a small Rhine town in the Rhineland-Palatinate, issued its own emergency currency during the hyperinflation spiral of 1923 — the period when German municipal and private issuers printed Notgeld simply to keep commerce moving as Reichsbank notes became worthless faster than they could be distributed. At 500,000 Mark, this denomination reflects the mid-to-late phase of that collapse; by November 1923, a single US dollar was trading at over four trillion Mark.

Conrad was a local printer, not a security printing house. The official stamp is doing the work that printing quality cannot.