Variable glaze color

[yedrow]

Is there a material, or a glaze property, that predicts if a glaze will generate one color at one thickness, and another at a different thickness, specifically when pooling?

Joel.

[Bill Kielb]

Tough to answer that question actually. Experience is best, trials are the best way and test tiles with good notes are super important. Experienced potters can tell you a lot of general properties of their glaze, but then again they have acquired the experience. Generalities for a celadon for instance might be darker color with more dramatic breaks and at some point perhaps too thick and it runs or crawls.

Test tiles likely are the best solution, one, two, three dip and so on.

Here is a shot of about 1/5th of the tiles from a Jon Britt workshop. Took him a long time to get this experience. If you go to a workshop you likely can gather some of that experience in on tenth the time or simply exchanging info with other potters often saves a bunch of time.

you can also search https://glazy.org/search?base_type=460&production=false&photo=false Many have pictures and notes on application. All for no charge.

 

[liambesaw]

Breaking glazes I've found are usually opacified with zinc or tin, but not always and not all of them do it.  I haven't noticed any chemical analysis that predicts it though.