This is an adaptation of the fluid simulation in Expresii to do Suminagashi ('墨流し' in Japanese), a form of paper marbling. Suminagashi is said to have originated from China and today it's called 水拓畫 in Chinese. What we show here is a WIP (work-in-progress) and has not yet released in the public version of Expresii.
We show that it's possible to load an image acting as obstacle for the flow, thus creating flow patterns that relate to whatever you put in that image. One useful application is making animated title sequence.
Changing the palette used results in interesting organic patterns. And what about applying the sprayer with suminagashi?
Let us know how you like it.