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The underglaze is the 20x5 cone 6 base transparent glaze (G1214M with 5% Mason 6666 black stain). Overglaze left: GR6-H Ravenscrag Oatmeal. Overglaze right: GA6-F Alberta Slip oatmeal. Both produce a pleasant silky matte texture. Double layering using typical dipping glazes is prone to crawling (because of shrinking and cracking during drying). By keeping layers fairly thin, it is possible to achieve success, but with glazes high in clay content (as these are), more is needed. A mix of raw and roasted Alberta and Ravenscrag Slips is the answer here. Start with a 50:50 ratio and adjust to establish a balance between drying hardness and drying shrinkage. For more assurance in production situations, mix the underlayer black as a base-coat dipping glaze.
There are enough variables that a record-keeping system is needed. Start now, and you won't regret it.

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At various thicknesses on M340, M370, P300. Fired at cone 6 oxidation using the C6PLST firing schedule.
For speckle add granular manganese (adjust the percentage to get the desired speckle density, start at 0.25%). Since the manganese particles are very heavy, and thus want to settle out, the glaze slurry should be thixotropic and stirred before each dip.
| Recipes |
GR6-H - Ravenscrag Cone 6 Oatmeal Matte
Plainsman Cone 6 Ravenscrag Slip glaze. See more at ravenscrag.com. |
| Recipes |
GA6-F - Alberta Slip Cone 6 Oatmeal
Plainsman Cone 6 Alberta Slip based glaze. It can be found among others at http://albertaslip.com. |
| Recipes |
G1214M - 20x5 Cone 6 Base Glossy Glaze
Developed by Tony Hansen in the 1980s. Its was popular for the simplicity and how well it worked with chrome-tin stains. |
| Glossary |
Reactive Glazes
In ceramics, reactive glazes have variegated surfaces that are a product of more melt fluidity and the presence of opacifiers, crystallizers and phase changers. |
| Glossary |
Glaze Layering
In hobby ceramics and pottery it is common to layer glazes for visual effects. Using brush-on glazes it is easy. But how to do it with dipping glazes? Or apply brush-ons on to dipped base coats? |
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