The following formulas will give an idea of the commercial brands on the market as sold in the dry powdered form: -

Branded White

10% Casein, alkali soluble, 5% Calcium hydrate,

85% Calcium carbonate,

20% Casein, water soluble, 80% Calcium carbonate,

20.20% Casein, alkali soluble, 12.00% Calcium hydrate, 67.75% Calcium carbonate, .25% Ultramarine blue,

15% Casein, alkali soluble, 10% Calcium hydrate, 40% Calcium carbonate, 35% Kaolin.

In these as well as the following formulas calcium carbonate (whiting) and kaolin can be used either alone or in varying proportions in combination.

Red

15% Casein, alkali soluble, 8% Calcium hydrate, 67% Calcium carbonate, 10% Oxide of iron red.

Brown

15% Casein, alkali soluble, 10% Calcium hydrate, 55% Calcium carbonate, 20% Burnt umber.

Blue

10% Casein, alkali soluble, 6% Calcium hydrate, 69% Calcium carbonate, 15% Ultramarine blue.

Yellow (Buff)

10% Casein, alkali soluble, 6% Calcium hydrate, 70% Calcium carbonate, 14% French yellow ocher.

Green

10% Casein, alkali soluble, 6% Calcium hydrate, 40% Calcium carbonate, 34% Kaolin, 10% Chronium oxide green.

Sandstone

15.00% Casein, alkali soluble, 10.00% Calcium hydrate, 73.00% Calcium carbonate, 1.75% French yellow ocher, .25% Vine black.

Greenstone

15.00% Casein, alkali soluble, 10.00% Calcium hydrate, 68.00% Calcium carbonate, 3.00% French yellow ocher, 1.75% Chrome yellow, D,

.25% Vine black, 2.00% Limeproof green.

Black

20% Casein, alkali soluble, 12% Calcium hydrate, 48% Kaolin, 20% Mineral black.

Gray

As above, but decrease black to 5%, and increase kaolin to 63%.

In the manufacture of casein cold water paints for interior work, as in churches, theatres, hospitals, sana-toriums, schools, etc., a great selection of color is at our command that could not be used for exterior painting. Therefore a great many varieties of color effects may be obtained. It is a fact well known that casein cold water paints are claimed to be washable, but this is true only of some brands and here only in a limited sense. For if these coatings were washed with water daily for a number of days, they would be ruined in a short space of time. Trials have been made to prolong the life of the paint and these were partly successful. The casein paint coatings were given an additional coating with a solution of alum in water, which proved satisfactory on interior walls, but not outside of buildings. Further trials with formaldehyde proved this rendering the casein insoluble on the drying of the paint and there are now any number of letters patent protecting the various methods by which this end is attained.