June 17, 2026
Brush with browser fame
Show HN: Inkwash, a watercolor sketching app and explanation
This browser watercolor app has people swooning — and begging for a mobile fix
TLDR: Inkwash is a browser app that mimics watercolor sketching and was largely built with AI, then explained in a very detailed write-up. Commenters mostly adored its look and feel, though one practical complaint stood out: on mobile, the controls eat too much of the screen.
A simple sketching app on Hacker News somehow turned into a full-on art-kid love fest. Inkwash is a browser-based watercolor tool inspired by real-life pen-and-waterbrush sketching, and the creator openly admitted the deliciously chaotic twist: the app was largely conjured with AI, then wrapped in a long explainer about how it works. That confession could have sparked a comment war, but instead the crowd mostly melted into a puddle of praise. The vibe was less “burn the robots” and more “wait, this is actually gorgeous.”
The strongest reaction by far? People are obsessed with how beautiful and satisfying it feels. One commenter flat-out said they wanted to bookmark it for explaining geometry to their son, which is maybe the nerdiest and sweetest endorsement imaginable. Another crowned the interactive explanation “the best part,” basically saying the app didn’t just look nice — it made a complicated idea finally click. That’s catnip for the Hacker News crowd.
Still, a tiny flicker of drama did appear: mobile users are not having the same dreamy experience. One person pointed out that the controls hog too much screen space on phones, which is the classic “love the app, hate the tiny-screen reality” complaint. There was also a subtle side-eye from someone asking if the creator had tried Rebelle, a rival watercolor toy, giving the thread a faint “okay, but how does it compare?” energy. In other words: pretty app, proud geeks, one mobile grievance, and just enough comparison-shopping to keep the comments spicy.
Key Points
- •Inkwash is a browser-based watercolor sketching app inspired by the author’s use of a waterbrush and pen for nature journaling.
- •The author says the project started as a test of Anthropic’s Claude Fable 5 and that the resulting app code was generated without the author directly writing it.
- •The app’s rendering pipeline uses floating-point textures for ink, fixed pigment, wetness, velocity, and pressure rather than storing final colors directly.
- •The simulation runs through roughly a dozen WebGL2 fragment shaders per frame, with a final display shader converting density data into the visible paper-and-ink result.
- •Water motion is based on Jos Stam’s Stable Fluids approach, with coarse-resolution velocity and high-resolution pigment fields to balance computational cost and visual detail.