In this video I’m answering a question I keep seeing pop up: if you see Paul Rubens “Gucai” being sold as “watercolor,” can you actually use it like watercolor on regular watercolor paper? I tested it on watercolor paper and compared it directly to Paul Rubens Watercolors (their pearlescent pans and tubes), and the big takeaway is that yes—you can get it to work—but it has quirks that make it feel very different from a normal watercolor painting experience. Gucai is a classical Chinese painting pigment system that’s really meant for more absorbent traditional papers like rice or mulberry, and that intended use shows. On cellulose or cotton watercolor paper, I don’t recommend it if you want typical wet-into-wet flow, easy glazing, and predictable washes. If what you actually want is a more enjoyable “traditional paint” experience, I share a few alternatives I’ve personally had better results with, and I also link my written review with still photos of the charts and swatches so you can zoom in and compare.