Egg Shell White has been made different ways over the years. The one thing they all have had in common is egg shells. The process here for a Egg Shell White is the most simple way we have found. This pigment can be used both as a white or as a extender of another color pigment.
WARNING pigment making of any kind can be dangerous to your health. Always use safety equipment such as gloves, eye wear and face mask. Do lots of research before you try anything. Know that any thing you do try is at your own risk.
First for the best white it is best to use white egg shells. Brown eggs and other colors will give the pigment a slight tint to it. If you wish you can wash the the outside of the shells with a little vinegar. This will dissolve the outer layer with the color in it.
Once you have the egg shells you wish to use, boil them for about 10 mins. This will clean them inside and out. Often a white foam will form on top of the water from left over egg white and other material in the egg shells.
With the shells boiled and cleaned all you need to do now is grind them in to a fine powder. This can be done with a mortar and pestle, a spice mill, coffee grinder or a ball mill.