Born in Munich in 1923, he dabbled with architecture at the Technical University before volunteering for the army in 1941.
After the war he spent several years in France, studying under, among others, William Straube who had been a pupil of Matisse.
In the 1960s, he developed his characteristic Abstract compositions, arranging diagonal or vertical lines of alternating colours to create dynamically rhythmical works of art. Fruhtrunk captured the mood of art lovers, enjoying considerable success and in 1968, he took part at the documenta 4 in Kassel as well as the 34th Venice Biennale.
Soon afterwards, Fruhtrunk created his most widely available work of art. In the early 1970s he was commissioned by the German discounter Aldi to produce a plastic shopping bag, which remained in service until 2018.
His 2ft 9in x 2ft 8in (83 x 81cm) oil painting, ET II, from 1971 is much more valuable: Karl & Faber in Munich is hoping to achieve €50,000-70,000 in the June 22-23 auction. Since 2016 the work has belonged to a German collector who purchased it at an auction in Milan. Before that it was part of an Italian private collection.