What does Yin and Yang mean in abstract paintings?
Yin and Yang is about polarities which cannot exist without each other: Light-dark, order-chaos, beginning-end, strong-weak, life-death, movement-stillness, above-under etc. Without evil we would not know what good is. We need the differences.
Yin is often associated with the static and immovable while Yang is visualized as movement and dynamic. Like earth and wind, rocks and water. Yin and Yang are like to different kinds of energy forms penetrating and driving everything in the universe. One of them cannot ever exist alone. So one say that it is in the deepest darkness of night that the dawn of light commences.
In an abstract painting you will soon realize the forces of Yin and Yang. One need to learn to let those polarities work with each other. If you in in your painting want to produce brightness you often have to introduce darkness. If your painting does not balance Yin and Yang forces it will easily loose tension and interest. A painting filled up with dynamic explosions can paradoxically end up in monotony - too much of the same. But if you then introduces order and calmness, tension and dynamic suddenly emerges again.
It is this balance of indefinite polarities which make an abstract painting interesting and fascinating: Polarities - like black/white, color opposites, forms/lines, repetition/variety, opaque/transparent, cold/warm, grey/brilliant colors - are in the same time fighting and collaborating with each other. Which creates painting as it creates the universe.