Glaze Testing: Triaxial Blend

This is the world of glaze mixing.  Weighing different ingredients on a triple balance beam.  Many of the materials used in glaze chemistry are toxic - best to wear a mask to avoid inhalation.

I experimented with glaze colorants recently.  A Triaxial Blend is a precise and mathematic way of testing different glaze colorants.  This is how it works:  take a glaze base that produces a surface you like and you know is stable (I chose Lau Luster, a cone 6 matte glaze).   Make three equal batches of the glaze and mix a different colorant in each batch.  I chose Copper Carbonate (produces a pale blue green) (A), Cobalt Carbonate (strong blue) (B), and Chrome Oxide (chartreuse) (C).  

The colors are methodically blended using a percentage of each.  Each cup has 5 tablespoons of glaze.  At the peak of each of the triangles is the pure glaze, then as you move towards the center the glazes blend with each other.  A tile in the center may be 20%A, 20%B, and 60%C, which would be 1 tbsp A, 1 tbsp B, 3 tbsp C, and so on.  

Test tiles and color chart.

Glazed test tiles.

A stripe of copper carbonate oxide wash on the back of each.

This is much easier to understand, right!  The glazed results.  You can see the spectrum of colors created by the blending of the glazes.  It's easy to tell here that Cobalt is a very strong colorant compared to the copper carbonate.  I like tiles 9 and 14.

Look how nicely the oxide reacts with tile 9 glaze.  So now I  have created a unique glaze and can mix up a batch using the new colorant combination.