Triaxial Glaze Blending
An often employed a way to develop new (usually visual) glaze effects. There are many books and web sites that cover this topic (and software to derive the recipe of the mixes). Triaxial is the most common form of blending (vs. linear, quadraxial). A factor that makes this type of blending easy-to-do is that corner or end points can be mixed as slurries (having equal specific gravities) and poured together by volume. Typically triaxial blend corners are labelled A, B and C. Mixes between corners, for example A and B in the photos below, are termed 3A-1B (75% A, 25% B), 2A-2B (50% A, 50% B), 1A-3B (25% A, 75% B). Mixes in the center of the triangle contain all three corners, they are 2A-1B-1C, 1A-2B-1C and 1A-1B-2C.
Tuning the degree of gloss on a matte black glaze
These 10 gram balls were fired and melted down onto a tile. The one the left is the original G2934 Plainsman Cone 6 MgO matte with 6% stain. On the right the adjustment has a 20% glossy glaze addition to make it a little less matte. Notice the increased flow (the ball has flattened more) with the addition of the glossy. In addition, while the percentage of stain is actually less (on the right), the color appears darker! Tuning the degree of matteness when making color additions to a base is almost always necessary to achieve a glaze that does not cutlery mark.
Tuning the degree of gloss in a colored matte glaze
Matte glazes have a fragile mechanism. That means the same recipe will be more matte for some people, more glossy for others (due to material, process and firing differences). In addition, certain colors will matte the base more and others will gloss it more. It is therefore critical for matte glaze recipes to have adjustability (a way to change the degree of gloss), both for circumstances and colors. This recipe is Plainsman G2934 base matte with 6% Mason 6600 black stain added. It has been formulated to be on the more matte side of the scale so that for most people a simple addition of G2926B (M370 transparent ultra clear base recipe) will increase the gloss. That means users need to be prepared to adjust each color of the matte to fine tune its degree of gloss. Here you can see 5, 10, 15 and 20% additions of the gloss recipe.
A triaxial blend of three glazes at cone 6
A is a matte white, B is Rich Iron Red and C is a glossy white. Recipes 1 and 2 are 75% A, 6 and 10 are 75% B, 9 and 12 are 75% C. 3, 4 and 5 are 50% A, 3, 7 and 11 are 50% B. 5, 8 and 11 are 50% C. This blend was done in 1977 in the lab at Plainsman Clays.
A triaxial blend of Getstley Borate and two native clays
The result is much less predictable than for blending existing known glazes, these reservoirs contain the runoff if the melted result is excessively fluid.
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