Theo van Doesburg made this painting "Counter-composition XV" with oil paint, but it's not dated. I find the primary color palette really striking, especially the black background. I bet van Doesburg was really thinking about how colors pop and vibrate against each other. There is a tension in the black that is offset by the cool diamonds that march across the canvas, like a distorted grid. The surface looks pretty smooth, but up close you can probably see the layers, where he built up the colors block by block. Everything feels so intentional, so considered, but there is something playful about the wonky angle of the red rectangle. It’s like he’s inviting us to question the rules of geometry! Van Doesburg's got that Constructivist vibe, maybe with a little bit of Mondrian thrown in. All of them remind us that art is a never-ending experiment, a constant conversation about what we see and how we see it.