# Undertint

> Watercolour pigment mixing, simplified.

Undertint is an iOS app that helps watercolourists predict colour mixes before committing paint to paper. It uses a physically accurate Kubelka-Munk subtractive mixing model to simulate how real pigments behave when combined — accounting for pigment properties like transparency, granulation, and staining.

## Key details

- Platform: iOS (currently in closed beta via TestFlight)
- Audience: watercolour painters — from intermediate learners to experienced artists
- Purpose: remove the guesswork from colour mixing by letting painters preview mixes digitally
- Technology: Kubelka-Munk reflectance model for physically accurate subtractive colour mixing

## Website

- URL: https://undertint.stach.ltd
- The marketing site features a real-time WebGL watercolour simulation as the hero section
- Beta sign-up is available through the site

## Contact

- Website: https://undertint.stach.ltd