What techniques may be adopted in an effort to vary the texture and opacity of a glaze?

Unit 7 Topic 11
Using Unity Formula

Blending techniques are the fastest way of obtaining an overview of the textural potential of a glaze.

Line blends are a basic tool used most frequently for exploring variations between two glazes. They can be used for exploring changes in texture or colour variations to mention only two of many possibilities for the technique.

The triaxial blend is most useful for exploring texture related variation in the flux balance of a glaze while maintaining a constant level of alumina and silica.

These blends can be used for any change sequence involving an original glaze varied in two directions e.g.

  • glaze A could be the original glaze
  • glaze B might be the original + more clay
  • glaze C might be the original + more silica.

Quadraxial or biaxial blends are excellent for revealing changes to a glaze resulting when a flux group is kept constant and the Al2O3 and SiO2 content is varied. e.g.

  • Take the original glaze and remove all sources of alumina and silica without changing the flux content. This becomes the glaze at corner C
  • Starting with the corner C glaze add clay such that the molecular parts in the unity formula for C is increased by say 0.6. This becomes the glaze at corner A.
  • Starting with glaze C add silica increasing the mol. parts for that oxide by say 4.0.This becomes the glaze at corner D.
  • Starting with glaze A add silica again increasing the mol. parts by say 4.0.This becomes the glaze at corner B.

The corner glazes are then blended using the volumetric techniques outlined by Ian Currie in his "A Systematic Approach to Stoneware Glazes".


Matrix automatically develops blends using this volumetric technique.

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