Jacoba van Heemskerck (1876-1923) was a female Dutch avant-garde painter, graphic designer, and stained glass artist, who contributed substantially to the development of modern art in the early 20th century. Back in the Netherlands after a formative period in Paris, where she trained under symbolist painter Eugène Carrière, she became affiliated with Piet Mondrian. Heemskerck as well as Mondrian were inspired by the anthroposophical teachings on color and form by Rudolf Steiner in the 1910s. While both artists sought to express spiritual experience through their work, Mondrian’s style became extensively geometrical over time, whereas Heemskerck developed an open, unconstrained and intuitive style of abstract symbolism. Her approach was received enthusiastically especially in German Expressionist circles. In the design of stained glass windows she later found the ideal medium to accomplish her long-pursued quest: to link the essence of color to light.