During his experiments with various photographic so-called "special techniques", he conceived in 1931 a tone-separation technique that was called "Izohelia" (known also as "Posterization"). The illustration presents an example of an image created in the technique, entitled "Highlander bagpiper of Poronin" (1937).
Experience aiding to develop this technique was gained by W. Romer during his work in his father Eugeniusz's publishing house "Książnica Atlas" in Lwow, where he managed the photomechanical department.