Pen-and-ink with living water — a fluid-simulation drawing app in a single HTML file.

Draw: https://johnowhitaker.github.io/inkwash/

About (WIP): https://johnowhitaker.github.io/inkwash/about

Demo video of a quick sketch here (Thread contains more examples)

The pen lays down dark ink; pressure and speed shape the line. The brush (hold the pen's barrel button, or press b) lays down water instead — ink flows, bleeds and blends only where the paper is wet, then gradually dries in place.

On iPad, the Apple Pencil draws and your finger is the water brush. Works on phones and tablets without a stylus too — the controls stay on screen.

Keys: b pen/brush · w white ink · d fix the drawing into the paper · f fullscreen · c clear · s save PNG. Sliders appear at the bottom edge.

No dependencies, no build — just open index.html in a browser (WebGL2 required).