Olle Bærtling (1911–81) was born in Halmstad in 1911 and moved to Stockholm at a young age where he worked as a bank clerk. In 1948 he started at André Lothe's painting school where he did not stay long, however, as he and his teacher had different views on contour lines in nature. Thus he transferred to Fernand Léger's painting school and laid the foundation for his future creations. Bærtling would become the foremost representative of a strictly geometric art in Sweden. He painted his first paintings with "open form" in the early 1950s. Before that, he painted in an expressionist style, before his non-figurative painting began to take shape. Bærtling was a concretist, he consequently consciously sought to distance himself from the representational. There his exploration of the dynamics of the triangular form and the ability of colors to reinforce the form with their color fields. An optical illusion where Bærtling's artwork tests us as viewers, as art is based on our ability to see. Patience and an open mind are of great importance.

“The art of the open form can be likened to the immaterial power and grandeur of the sky, infinite space: it is organized light, strongly dynamic in infinity. The work is conceived and formed as an instrument, the dwelling place of the spiritual nature is the real work.”

The paintings are dominated by triangular fields with black contours that meet with sharp angles, horizontal and vertical lines. Open forms that give the impression of continuing beyond the boundaries of the picture. An extension of the room, straight out into space. “Baertling’s work extends beyond this into space, the outer contours that he leaves our imagination to anticipate.” He also translated the contours into sculptures. Where they assumed a floating character with their black lines against the sky. Olle Bærtling is the “master of open form”, an extension into infinity.