IWhy color your own clay?
You can purchase pre-colored clay but if you want more control over color and hues I would recommend mixing your own. You can use any clay body, but white clays firing at or above Cone 6 provide vibrant color results. I prefer to mix the stains into wet clay bodies but some people do mix dry stains into dry clay before hydrating. The Mason Stain Company has a very informative web site with colors recommended for clay bodies.
Though many other stains work very well with clay bodies, you do have to buy a small sample and test them first with each clay body.
One supplier I called would not tell me what the basic clay body was that they were making it from. Without this information it is impossible for me to lighten their pre-set color or use white along with it to make a pattern.
I like vibrant colors and use a lot more Mason Stain by % than they do. I can always lighten them up by adding white.
Even though it is a messy job, it is also a very simple job to color clay.
I always add a high percentage of color to my clay because mixing is such a messy job and it is very easy to add white clay later to lighten the colors. It’s also much easier to store 20 lbs of concentrated colored clay then 80 pounds of pastels.
My basic Mason Stains with percentages.
#6020 Pink @ 15 – 20 %
#6450 Yellow @ 15 – 20 %
#6300 Blue @ 6 – 8 %
#6242 Bermuda Green @ 12 – 15 %
#6600 Black @ 6 – 8%
In order to avoid the dust problem, mix the Mason stains in a sealed plastic bag with just enough water to create a creamy solution. Then create a well in your clay and pour in the mixture. Knead the clay until you like the color result.
I use my mixer to knead in the stain solution until the color is even throughout the clay body. You want the finished clay to be soft as cookie dough. My mixer is a Hobart A120T and is 1/2 hp. I bought it used.
Usually you mix the clay until the color is even, but you can also stop mid way to get a nice speckled effect with the color.
I always make sample discs of each color for reference. You cannot count on each batch turning out exactly the same. I also make sample discs of the colors combined with white clay and with each other.
I hear comments about how expensive stains are but consider that colors last a long time, especially if you are mixing in plain white clay. I keep colors stored in plastic bags for years with no ill effects.
Another area of concern is safety. You do have to be careful not to inhale the dry powder while mixing, so use a proper breathing mask. After that is done, the stains are safe to work with and fire. Some people choose to wear latex gloves.
I have experienced fluxing with some stain colors when they are used in a very concentrated form so you do have to prevent them from sticking to the kiln shelf. I sprinkle some alumina hydrate under them when firing these.
Choosing the Right Mason Stains
The Mason website has listings of all the colors available with a guide showing which ones are suitable for using in clay bodies and which ingredients to avoid in your clear glazes.
Why does this matter? Every clay body has ingredients in it that can react to a colorant. Sometimes that lovely pink fires green or the blue fires pink because of it. If your clear glaze has the wrong ingredient in it, it will change the colors or bleed them.
You can be reasonably safe if you stick with their guidelines, but safe is not always fun. I have tried dozens of other stains with great results. The trick is to test every single batch you blend in order to see what happens to the color with and without a glaze. Then you can decide whether to keep using it or not.
I had a pink stain that fired the most lovely pale green. I liked it and kept using it, but since I have the attention span of a gnat, I quickly forgot the pink was really green and ruined a pattern with the wrong color.
This is why I use the ones that look like the end product.
I would encourage you to buy an ounce or so of different colors and give them a try. Some are incredibly beautiful and are colors you cannot achieve by simply mixing two primaries.
For more options and information on coloring clay, look at the WORKSHOP page of my site to find a class near you. If there isn't one, consider recommending my workshops to an Arts Center in your area.workshop area.