Gertrude Bohnert married her colleague, the painter Hans Erni in 1946. Their daughter Simone Erni (*1946) also became a famous Swiss painter and graphic artist. In the late 1920s, Bohnert studied at the School of Arts and Crafts in Luzern and the Academy Julian in Paris. She also made several study trips throughout Europe. She started as a porcelain painter, but was best known as a glass and crystal engraver. Her objects were mainly decorative animal and plant patterns. Later, she also produced glass sculptures. Bohnert was killed in 1948 in a riding accident.
Switzerland