These underglaze crayons can be used to draw on greenware or bisqueware. The work can then be glaze-fired normally.

Difficulty Level: easy      Time Required: 120 min

Here's How:

1. Ingredients: White Firing Ball Clay (50%) Potash Feldspar (25%) Flint (Quartz) (25%) Bentonite (5%) Colorant (15%) (Iron Oxide, Copper Carbonate, Cobalt Oxide/Cobalt Carbonate or any undeglaze colorant).
2. Mix the ingredients with the desired colors and dry sieve the powder through an 80 mesh.
3. Weigh the ingredients and then measure out 45% of that weight in water.
4. For every 100 gm (4 ounces) of powder, mix in a teaspoon of sodium silicate to the water.
5. Add the water to the powder and mix thoroughly with a fork or similar tool.
6. Roll into a pencil shapes.
7. After drying, fire the pencils/crayons to 800^o - 900^o C.
   

1. Be sure to wear a mask and gloves, if using toxic colorants.
2. Experiment with different color percentages.
3. Try out making pencils of different sizes, for different drawing requirements.
   

Related Resources:

• Ceramic Toxic Materials