Kasimir was born in 1881 at Pettau, today Ptuj, Slovenia, then a part of the Austro-Hungarian monarchy. He inherited his talent from his ancestors; his grandfather was a painter and a poet, and his father an officer in the Habsburg army, who later became a professional painter. Kasimir attended the Vienna Academy of Art where he studied under William Unger, who introduced him to the technique of the coloured etching, and also to his future wife, the artist Tanna Hoernes.[1] He died in 1962 in Grinzing, a suburb of Vienna.

Kasimir was among the first to develop the technique of the coloured etching. Before this, prints were usually hand-coloured with the colour being applied in a casual, haphazard manner. Kasimir would first create a sketch—usually in pastel. He then transferred the design on as many as four to six plates, printing one after the other and applying the colour on the plate—all done by hand