Glaze Testing
Sally Brogden, University of Tennessee, April 2010
SAMPLE COLOR RUN
1. Base Alone
2. Iron oxide 2 %
3. Iron oxide 4 %
4. Iron oxide 8 %
5. Cobalt carbonate .5 %
6. Cobalt carbonate 2 %
7. Cobalt carbonate .5 % + Iron oxide .5 %
8. Copper carbonate 1 %
9. Copper carbonate 3 %
10. Copper carbonate 4 %
11. Copper carbonate 2 % + Rutile 4 %
12. Chrome oxide .25 %
13. Chrome oxide 1 %
14. Copper carbonate 2 % + Cobalt carbonate .5 %
15. Manganese diox powder 1 %
16. Manganese diox powder 3 %
17. Titanium dioxide 15 %
18. Nickel oxide 4 %
19. Rutile 4 %
20. Rutile 8 %
21. Tin oxide 6% + Rutile 3 %
22. Tin oxide 6 % + Copper carbonate 3 %
23. Superpax / Ultrox 10 %
24. Mason Stains 8-10 %
To ensure accurate results: 1) Weigh twenty-four 100 gram batches of glaze base and
combine with water in labeled test cups. 2) Weigh colorants using metal gram scale pan
and add directly to appropriate cup. 3) To avoid clumping, wait for water to soak through
dry ingredients before mixing. 4) Mix, adjust consistency and brush onto labeled test
tiles.
GLAZE TESTING / PROCEDURES
1. CALCULATE BASE
Calculate the amount of glaze base needed for the number of desired color tests.
Multiply base recipe by the number of color tests plus one. For example, for the 24 color
runs above, multiply base recipe by 25. A 100 gram base would yield a 2500 gram
batch.
2. WEIGH LARGE BATCH
Weigh out, and dry mix the 2500 grams of glaze base. Store in a heavy weight garbage
bag. To dry mix, secure garbage bag and tumble well.
3. LABEL CUPS
Label large plastic cups for each color test: 1 - 24.
4. WEIGH 100 GRAMS
Weigh out premixed base into 24, 100 gram batches: 100 grams for each color test.
Place each 100 gram batch on a separate sheet of newspaper.
5. ADD H20
Place @ 1.5” of water in each labeled cup. Add 100 grams of base to each cup of water.
Adding the dry to wet ensures that the glaze base will settle into the water without
clumping.
6. ADD COLORANTS
Once all 24 cups have wet base in them, very carefully weigh out colorants placing each
into the CORRECT cup as you work. Use metal pan to weigh colorants. Mix and adjust
glaze consistency.
7. LABEL TILES
Label test tiles with initials for base + color run #. For example Base A-1, A-2, etc. Use
red iron oxide wash or glaze pencil for labeling.
8. APPLY GLAZE
Apply Glaze to test tiles by dipping or brushing.
9. FIRE
Wear a respirator when working with dry ingredients!
Glaze Testing & Calculation Resources
Triaxialblend.com
http://www.triaxialblend.com/default.aspx
Matrix http://www.matrix2000.co.nz/MatrixV6Help/Overview_Introduction.htm
Clay and Glazes for the Potter, Daniel Rhodes
Cushing’s Handbook: Glazes, Glaze Calculation & Formulation, Val Cushing
The Potter's Book of Glaze Recipes, Emmanuel Cooper
The Ceramics Spectrum, Robin Hopper
Those Celadon Blues, Robert Tichan
China Paint & Overglaze, Paul Lewing
Anderson Ranch Art Center Ceramic Glaze Book