Material Selection
The tattoo artist selects materials that can be ground up to provide color. These materials can be virtually anything, even coffee grounds (though anything put inside your body should be chosen with caution), and are selected based on the color desired for the ink. Tattooists frequently use chemical compounds such as iron oxide (to create a common rust or red color) and zinc oxide (to create a white color) in their inks. They get material to make inks from other natural sources as well, such as mustard seed and dried flowers. The wide variety of material options available means a tattooist can get virtually any color desired and he can mix grindings together to create his own colors.
Grinding
The tattooist grinds up the materials selected until they are reduced to fine powders. Usually this is done with a common bowl and pestle set, but the tattoist can use anything that grinds, such as a cheese grater, blender or even two flat rocks (though caution dictates that anything used to grind inks should be sterilized first). This is part of what makes the manufacture of Indian ink different than commercial tattoo ink--commercial inks are not ground by hand and commercial inks also can contain synthetic additives.
Mixing
The tattooist mixes the powders, if needed, to get colors not otherwise available or colors specially requested by the person getting tattooed. This is comparable to a painter mixing paints on a palette. The person being tattooed can have a say in what is mixed together to get the exact color he wants.
Fluids
The tattoo artist mixes the powder with a carrier (a fluid that will make the powder like a runny paste). A carrier can be anything from water to witch hazel. Ethyl alcohol is a common carrier.
Heating and Cooling
Depending on the type of powder and carrier selected, the tattoo artist may elect to heat the powder and carrier mixture to get a more even pigment distribution throughout the ink or to change the consistency of the ink. The ink, if heated, is cooled before use.
