5 000 000 Mark

Pößneck is a small industrial town in Thuringia, and like dozens of German municipalities in the summer and autumn of 1923, its city treasury issued emergency Notgeld when the Reichsbank simply could not supply banknotes fast enough to keep pace with hyperinflation. What sets this note apart is the substrate: genuine leather, not paper. Several German municipalities experimented with unconventional materials — silk, velvet, linen, aluminum foil — partly as a practical measure to produce something durable and difficult to counterfeit, partly because novelty items were known to be hoarded by collectors rather than spent, effectively letting issuers profit from unredeemed notes.

The watermark feature on leather is the genuinely curious detail here. Achieving a watermark effect on hide rather than paper requires a different mechanical process entirely, likely an embossed or blind-pressed pattern rather than a true papermaking watermark.