Reactions at the interface between two glazes
The interaction at the interface of adjacent glazes.
Several closeups of the interaction region of the two glazes are shown and,
for context, a picture of the pot.
The background glaze is paperWhite_ZV_Z2E_3_2F, the foreground design is
glazed with hankPaper_Z1R_2C_1, and contains cobalt and copper.
The design is created by adhering a mask and then applying the main
glaze. After drying, the entire pot is coated in wax,
150 deg F an hour to 250 deg F
400 deg F an hour to 1800 deg F
300 deg F an hour to 2050 deg F
120 deg F an hour to 2310 deg F with a hold of 20 minutes at 2310 deg F
300 deg F an hour to 1750 deg F then a half hour hold at 1750 deg F
300 deg F an hour to 1700 deg F then a Three hour hold at 1700 deg F
25 deg F an hour to 1650 deg F then a one hour hold at 1650 deg F
K2O 0.09
Al2O3 0.54
SiO2 3.16
molecular percent Silica 65%
K2O .13
Al2O3 .42
SiO2 2.7
molecular percent Silica 63%
Added:
1% cobalt carbonate
The background glaze and inlay glaze belong to different glaze families. The
background glaze is high in strontia with
The inlay glaze flowed through the background glaze, the result of an
extremely generous glaze application.
The high viscosity of both
background and inlay glazes allowed such a generous deposit of inlay glaze.
The viscosity of these two glazes is a consequence of the firing, which is
near the bottom of the
The patterns created by the flow of the inlay glaze through the background
glaze reveals the compositional
Interestingly the presence of copper in the inlay glaze is not apparent.
then the mask is removed
and the open area filled in with a second glaze.
Close up Images of the interaction region
Image of the piece
bowl with glaze paperWhite_ZV_Z2E_3_2F and inlay hankPaper_Z1R_2C_1
bowl is ~7 inches in diameter
oxidation firing to cone 10 in an electric kiln
Firing profiles
Up Fire profile
Down Fire Profile
Clay body is a grolleg porcelain from Tacoma Clay Art Center.
glaze compositions
Background glaze
Empirical Formula paperWhite_ZV_Z2E_3_2F :
Na2O 0.09
Li2O 0.18
CaO 0.01
MgO 0.02
SrO 0.61
TiO2 0.15
Inlay Glaze
hankPaper_Z1R_2C_1 :
Na2O .12
Li2O .05
CaO .14
MgO .02
BaO .3
SrO .24
TiO2 0.14
0.7% Copper Carbonate
Remarks
minimal calcia and magnesia;
the inlay glaze contains both calcia and baria.
The surface coverage of the inlay is
nearly 3x what it had been in the application.
respective maturation temperature ranges.
variations within both glazes.