Lime Wash & Fresco Paint
Pigments mixed into lime, painted into wet plaster — Pompeii, Giotto, the Sistine Chapel.
Spread wet lime plaster on a wall, then paint pigment-and-water into it before it dries.
- ▸As the plaster sets, the color becomes part of the wall, not on top of it.
- ▸You only get a few hours per patch, then it's locked in forever.
- ▸How Michelangelo painted the Sistine Chapel.
Steps
- 01
On a tile, mix pigment with a little water to a smooth paste.
- 02
Stir the pigment paste into a small amount of slaked lime + water (lime-water).
- 03
On the wall, apply fresh wet lime plaster (the intonaco).
- 04
Paint the colored lime-water into the still-wet plaster — the lime carbonates and locks pigment in.
- 05
Work fast: only paint what you can finish before the plaster sets (a giornata).
Materials3
- — Slaked lime putty
- — Lime-fast pigments (earth ochres, oxides, lampblack, ultramarine)
- — Distilled water
Safety
Involves caustics, acids, or open flame. Full PPE and trained supervision recommended.
- Caustic alkali — burns skin, eyes, lungs
- ☐Wear chemical splash goggles and nitrile gloves
- ☐Add alkali to water, never water to alkali
- ☐Keep vinegar nearby to neutralize spills
- ☐Work in a ventilated area; keep food and drink out of the studio
- ☐Read each material's safety data sheet (SDS) before starting
- ☐Have water, soap, and a first-aid kit accessible
Heuristic guidance derived from listed materials. Always consult each material's safety data sheet (SDS) and a qualified instructor before attempting.
Notes
Only alkali-stable pigments survive lime. Once cured, fresco lasts millennia.