Glaze Inlay in Silvery Oil Spot Glaze
cone 10 oxidation
Firing profile
Up Fire profile
150 deg F an hour to 250 deg F
400 deg F an hour to 2050 deg F
120 deg F an hour to 2250 deg F
60 deg F an hour to 2310 deg F with a hold of 20 minutes at 2310 deg F
Down Fire Profile
A half hour hold at 1750 deg F
A three hour hold at 1700 deg F
slow downfire at 25 deg F an hour in the interval 1700 deg F to 1650 deg F
A one hour hold at 1650 deg F
Clay body is a grolleg porcelain from Tacoma Clay Art Center.
Second glaze inlay in the silvery oil spot glaze - a closer look at the interface between the two glazes.
Here is the previous work on the silvery oil spot glaze.
The surface texture of the mashiko glazes is dominated by the oil spots, which
often are large and heavily dimpled,
but even when not dimpled these
glazes are active to the time when the glaze solidifies. the result is that the
interface between
the background mashiko glaze and a contrast glaze is a
dynamic part of the design. I show several examples
of this with
pictures both of the pot, and a close up of the boundary between the
background glaze and inlay glaze.
Note the irregular boundary between the two glazes, the cutouts in the inlay
glaze which has been etched by the
background glaze. Notice also the
band about the inlay which is distinct from both the ground glaze and the
inlay glaze.
The glazes candaceBlackB and satIron_ZJ_1PPP are closer in chemistry to the
background mashiko glazes, resulting in a less
'violent' encounter at the
interface.
The bowls are ~ 5 inches in diameter, the plate 9 inches in diameter.
The pot is shown on the left, a detail from it on the right.
The inlaid second glaze decoration is created by applying a glaze over a
mask,
waxing, the glaze and mask, then removing the mask and filling in
the second decorative glaze.
background glaze mashiko_ZJ_1 inlay paperWhite_ZK_2 + CR
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background glaze mashiko_ZJ_0_N inlay paperWhite_ZI_2 + Cobalt and Crome
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background glaze mashiko_ZS_3_EU inlay paperWhite_ZI_2 + Cobalt and Crome
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background glaze mashiko_ZJ_0 inlay CandaceBlackB
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background glaze mashiko_ZS_4 inlay CandaceBlackB
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background glaze mashiko_ZJ_0 inlay satIron_ZJ_1PPP
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glaze compositions
Average Emperical Formula mashiko_glazes
K2O 0.13
Na2O 0.12
Li2O 0.11
CaO 0.22
MgO 0.42
Al2O3 .84
Fe2O3 .23
SiO2 5.8
molecular percent Silica 74 %
composition decorative inlay glazes
Emperical Formula satIron_ZJ_1PPP
K2O 0.02
Na2O 0.31
Li2O 0.25
CaO 0.4
MgO 0.02
Al2O3 .49
Fe2O3 .21
SiO2 3.2
P2O5 0.13
molecular percent Silica 63 %
Emperical Formula candaceBlackB
K2O 0.33
Na2O 0.14
Li2O 0
CaO 0.4
MgO 0.13
Al2O3 .62
Fe2O3 .24
SiO2 5.4
molecular percent Silica 74 %
paperWhite_ZI_2
K2O 0.1
Na2O 0.36
Li2O 0.04
CaO 0.03
MgO 0.3
SrO 0.17
Al2O3 .49
SiO2 2.5
molecular percent Silica 60 %
paperWhite_ZK_2
K2O 0.21
Na2O 0.23
Li2O 0.05
CaO 0.2
MgO 0.01
SrO 0.3
Al2O3 .6
SiO2 3
molecular percent Silica 63 %