His works are influenced by Serbian icon painting, wood-engraving and pop art.

In Ternitz in Lower Austria, they lived in the village Pottschach, where Hammerstiel remained a resident for life.

[2]: 6 Hammerstiel took part in a competition of the Austrian Federation of Trade and won a prize, which resulted in studies of art.

[2]: 7  His works were exhibited in the Austrian Culture Institute in New York City, where he was exposed with American painting, and used radically bright colours for his compositions.

[2]: 4  He was the author of Von Ikonen und Ratten: Eine Banater Kindheit 1939 – 1949 (with 32 woodcuts, Brandstaetter: Vienna, 1999); and illustrator of several books including Des Bischofs Kleid by Luisa Owens (2013).

[1] Andrea Mayer, Secretary of State in the Ministry of Culture of Austria, described his work as unique in the Austrian art scene, based on many regional traditions.