It has always been difficult to simply place Olle Baertling's artistic career within a specific -ism or artist grouping in Swedish art history. He was an independent artist who charted his own course both in life and in art. Olle Baertling long felt that there was a resistance to his art; he was "the constantly controversial banker who tried to paint" in Sweden. Many artists have, of course, experienced resistance when they innovatively and creatively presented something new to the public, but in Baertling's case, one might feel that it was unfair and petty, as he, unlike many of his contemporaries, reached far beyond his homeland's borders even during his lifetime.

The 1950s were Olle Baertling's most important decade. During the early years of the 50s, he took longer and longer leaves from his banking job at Skandinaviska Banken and travelled to Paris. There, in the Mecca of art, he came into contact with the new at the Salon des Réalités Nouvelles and sought out artists such as André Lhote, Fernand Léger, Victor Vasarely, Richard Mortensen, and Auguste Herbin. The latter became crucial for his continued development as an artist. Herbin introduced Baertling to the forward-thinking gallerist Denise René, who immediately included Baertling in her "stable" of constructivists. Baertling abandoned the OP art that had inspired him for a time and began to create a style of his own, where triangles and diagonals became the main theme. Once Baertling had committed himself to the non-figurative, he began to "construct" paintings. From geometric basic elements, he built a new pictorial world of proportions, relationships, and synthetic, programmed colour harmonies. Everything was methodically executed; the geometric instinct took over, and "the open form" was born. In the concept of "the open form," Baertling sought to depict space and movement through his geometric shapes that continued beyond the surface of the canvas, everything that existed within the picture plane was pushed out to the edge of the frame and beyond.