Calcined Kaolin

Description

Calcined kaolin is produced by heating ultra fine natural kaolinite to high temperatures in a kiln. The calcination process increases whiteness and hardness and alters the size and shape of the kaolin particles. Calcined Kaolin is used as paint extender (specifically titanium white) and in grounds for painting support in iconography or gessoes. In ceramics, calcined kaolin is used in glazes because it will not shrink while being fired.

Calcined Kaolin can be used in the traditional chalk, clay and milk paint recipes to preserve whiteness, however “calcining process” removes water molecule from the kaolin which removes its “suspending” properties (liquid will separate and the filler will settle at the bottom). Therefore if added to the limewash it will add to the opacity and keep pure white color of the lime, but will not help to keep the lime and other paint solids in suspension without the addition of natural raw kaolin (uncalcined) which is slightly off-white if used by itself.

Simple Milk Paint recipe:

Mix dry

– 3 parts of Artist Chalk
– 2 parts of Powdered Lime
– 1/2 part Art Casein

– 1/4 – 1/2 part Natural Kaolin Clay (optional and for painting grounds)
– 1/12 Salt (optional and for painting grounds)

add 2 quarts of water mix thoroughly, add more water if needed (depending on desired effect and surface)

– if needed, add mineral pigment for color

WARNING: This product can expose you to chemicals including Silica, crystalline (airborne particles of respirable size), which are known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov.