Ravenscrag Base under a selection of other glazes.

[George Lewter]

One of the touted qualities of Ravenscrag Slip Glazes is that they are supposed to layer well.  For layering tests I throw a ring of clay and mark 10 areas around the circumference. I dip or brush the walls of the ring in the base glaze and then brush in each of the zones all the glazes I want to test over that base glaze.

 

For this test I used the cone 6 Ravenscrag base recipe (80% Rav.Slip + 20% Frit3134). I brushed the walls of my raw, bone dry test ring with the base glaze and then brushed on the other selected glazes from my stock to see how they layer over the Ravenscrag glaze.  The ring of Laguna #80 brown stoneware was single fired to cone 5 1/2, held for half an hour, cooled to 930 C held for an hour and cooled naturally to room temperature.

Photo 1 Left to right with RS base all around the circumference.

A - ravenscrag base glaze with 12% addition of buttercup yellow stain.

B - C. Harris Temoku

C - Spectrum Texture Iron (commercial prepared glaze)

 

Photo 2 left to right

D - Spectrum Texture Autumn (commercial prepared glaze)

E - Jen's Juicy Fruit

F - Hannah's Fake Ash Blue

 

 Photo 3 Left to Right

F - Hannah's Fake Ash Blue

G - AMACO PC-46 Lustrous Jade (commercial prepared glaze)

H - AMACO PA-40 Pompeian Ash (commercial prepared glaze)

J - Extreme Right - Light Stormy Blue from MC6G - Crawled badly.