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The bisque fired test tiles from One Test Tile are upright, ‘ T ‘ or ‘ L ‘ shaped test tiles made from clay that has been extruded, evenly cut into 1-3/4″ sections, lightly sponged to remove sharp edges, then bisque fired to Cone 04. 


Bisque fired test tiles can be used to try different glaze combinations, to find out how a particular glaze will look on a specific clay body (for example, a transparent blue celadon will look very different on a dark brown clay, than it will on a porcelain clay).

They can also be useful if your trying out new underglaze colors or brands with regular glazes, to test for opacity/transparency, to find out how well they work together, or to find out if the underglaze colors will burn out, disappear, feather or bleed in unintended ways when glazes are applied.

Cone 6 and Cone 10 refer to different firing temperatures for clay and glazes.

Frequently, Cone 6 work is fired in an electric kiln and Cone 10 work is fired in a large gas, or other atmospheric kiln, like a wood, salt, or soda kiln.

The test tiles from One Test Tile are identifiable by their shape:

Cone 6 tiles are ‘ L’ shaped and

Cone 10 tiles are (upside down) ‘ T ‘ shaped.

These test tiles also have the name of the clay body and firing temperature stamped on the bottom, so you never have to wonder or guess what the clay or firing temperature is.

Absolutely! There are many ways to make your own test tiles.

In fact, after you test your glazes, oxides, underglazes, and other materials on a basic test tile, and get the desired results, the next useful step is to test your results on a quick, simple piece that is the same (or similar) in shape to the work you want to make and see if you get the same results.

  1. Mark the bottom of the tile with an underglaze pencil or mini-brush and liquid underglaze.
  2. Brush a thin layer of wax over your writing.
  3. Dip the top of the test tile in your glaze (do not glaze any part of the foot).
  4. Dip the top right or left corner.
  5. Fire your tile.
marked test tiles