1 Pfennig - Gerresheim Glashüttenwerk vorm. Ferd. Heye

Gerresheimer Glashüttenwerke, founded in 1864 outside Düsseldorf, became one of Germany's most important industrial glassmakers — and by 1917, the wartime metal shortage had pushed even large private manufacturers to issue their own notgeld coinage to pay workers when Reichsmünzen had effectively vanished from daily circulation. Zinc was the compromise material of the war economy: iron and copper were military priorities, and aluminum supplies were similarly constrained.

Factory-issued pfennig pieces of this type rarely survived in quantity; workers spent them, lost them, or discarded them once the emergency passed.