50 Céntimos Berja

Berja is a small municipality in Almería, and like hundreds of Spanish towns, its ayuntamiento issued emergency fractional paper money during the Civil War after metallic coin vanished from circulation almost entirely by late 1936. These local issues — collectively known as paper moneda local or billetes de necesidad — were produced under desperate conditions, often on whatever paper and printing equipment the town hall had to hand. Quality control was not the priority; getting something exchangeable into local hands was.

The official stamp is the only security feature, which tells you everything about the trust model: it worked because people had no alternative.