C/6 Glaze Resource

The glaze bases represented here are a growing project.  There is a base test tile for each base recipe and nine additional tests with colorants/ opacifiers added for a variety of colors. Search by base glaze name, hue, surface quality, opacity, or colorant in the sidebar , drop-down archives. The Base Glaze Notes Page has additional information on each recipe...

Using This Resource

This resource is meant as a starting place.  Conduct your own tests before using these glazes on your work.  Due to differences in firing schedules, kiln fluctuations, thickness of application, clay body and other variables test will significant variations to tests pictured on this site. These glaze tests here are a rough guide to what is possible. These tests are intended to show what may be possible for many surface solutions. Each artist is responsible for their own application and testing for functionality of use on utilitarian ware.

How the Test Tiles were Fired

Each of the glazes on this page was tested in an Electric Kiln, fired to cone six, on Mac 6 Porcelain (pictured left), Coleman Raku (middle) and Oregon Red (right) made by Clay Art Center in Tacoma Washington. These are the clay bodies that we enjoy using... 

Each test tile was thrown, given horizontal ridges on the wheel, and bisqued to c/06. The glazes were poured over the surface for the first layer and the dipped half-way down from the top for the second layer. The second dip was done to show how thickness changes the glaze characteristics. Different AMACO Velvet Underglazes were applied with a brush under each tiles first layer of glaze.  The underglaze number is noted on the Glaze Notes page. Finally the tests were fired to cone six in a Skutt electric kiln.

Glaze Firing Schedule

Here is the ramp/hold schedule we use for our Cone 6 glaze firing. The end temperature can vary depending on the size and age of your kiln, always use a witness cone to double-check.

Ramp 1   100º an hour
Up to       220º
Hold        0.05 Minutes

Ramp 2   200º an hour
Up to       1000º
Hold        0.05 Minutes

Ramp 3   200º an hour
Up to 2180ºf
Hold        0.05 Minutes

Reading a Test Tile

When admiring a glaze test tiles, ask yourself, "Which exact part of the surface is it that I am drawn to on this specific test?"  Is it the shine, the way the glaze changes, is it where the underglaze is interacting, is it the thin or thick area? Is it the texture of the clay coming through or the texture of the test tile? Try to dissect what you see to understand if this quality would truly work well with the surface development of your work. And try to figure out if you want this surface entirely covering or only in certain areas?

Books on Cone Six Glazes

Cone 6 Glazes by Michael Bailey
Cone 5-6 Glazes: Materials and Recipes by Ceramic Arts Handbook Series
Glazes and Glazing: Finishing Techniques by The American Ceramics Society
Mastering Cone 6 Glazes by John Hesselberth & Ron Roy
The Complete Guide to Mid-Range Glazes: Glazing and Firing at Cones 4-7 by John Britt
Electric Kiln Ceramics: A Guide to Clays, Glazes, and Electric Kilns: Richard Zakin, Frederick Bartolovic, Sherman Hall

The Glaze Galleries!

Each image in the gallery will show the recipe with colorant when you hover the cursor over the image...

Additional INFO: Glaze Base Notes.

These drop down archives are for searching by characteristic. Select from color, oxide, surface quality or opacity! There is one archive for shinier glazes and one for more matte glazes...

Make your own test-tiles!