When designing their early-pattern Drillich workwear in the 1930s, the German military explicitly modeled their design after the French Army's Bourgeron work jacket. The French Bourgeron prominently featured a clean, minimalist hidden-button fly closure, which the Germans adopted for their own unbleached linen sets.
It was built specifically as a chore uniform. Soldiers wore this unbleached linen jacket over their main uniforms to protect them from engine grease, mud, weapons cleaner, and coal dust while building fortifications, cleaning vehicles, or doing camp tasks.
