Casein Paint

You will need:
casein, 50 g
hartshorn salt (X), 15 g
water, 150 cc
spikenard oil, 10 drops
glass plate, 30 x 30 cm
glass paint rubber
2 palette knives
water and detergent to clean equipment and brushes
medium pan (when hartshorn is added the mixture effervesces)
measuring jug
wooden spoon
jar with lid
pipette / eye dropper

Fill the pan with 150 ml water and add the casein. Allow to swell for 2 hours. Put 15 g hartshorn salt in the glass. Add water in small amounts (50 ml max.) and stir until  dissolved. Turn on the extractor and take the pan off the heat. Add the salt solution in small quantities. The mixture will start to effervesce. Keep the pan under the extractor to draw off the ammonia fumes. Keep stirring until the foam subsides. After a while the glue becomes transparent. It is then ready for use. Place a teaspoon of pigment on the glass plate and moisten with water from the pipette. Mix the mass well using the palette knives. Move the glass rubber over the mass with a powerful circular motion. Add the casein in small amounts and rub until you get a beautiful paint. Keep the paint in a well-sealed jar in the refrigerator. Conserve with 10 drops spikenard oil (a type of lavender oil). As long as you can smell the spikenard oil, it’s doing its job.

Useful tips
Use an electric mixer for wall paint. The colours do not darken, unlike oil paints. Bronze powders make up very well into casein paints. Powdered slate gives a dark, silvery colour. The casein, once prepared, will start to decay after about a week unless conserved. If you need to keep it longer, add 10 drops spikenard oil after the foam has  subsided. Stir well or it will not mix.