reacting Glazes
The background glaze is oribe-woof-black; the inlay design is glazed with
hiAlk_Z3P_MAl.
The inlay design is created by adhering a mask and then applying the main
glaze. After drying,
The matrix (i.e. background) glaze and inlay glaze do not overlap before
firing. The width of the
Diffusion of titanium, and alkali metals from the inlay into the matrix,
created a banded pattern
The matrix glaze is high in alkaline earths, calcium and magnesium. It
also is high in silica and
The inlay glaze is high in alumina and contains titanium, resulting in a stiff
glaze with rutile crystals.
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 1850 deg F then a 2 hr hold at 1850 deg F
300 deg F an hour to 1750 deg F then a 1 hr hold at 1750 deg F
300 deg F an hour to 1700 deg F then a 3 hr hold at 1700 deg F
25 deg F an hour to 1650 deg F then a 1 hour hold at 1650 deg F
K2O 0.10
Al2O3 0.41
SiO2 2.97
molecular percent Silica 66%
added:
5% copper oxide
K2O 0.12
Al2O3 0.60
SiO2 3.28
molecular percent Silica 63.4%
the mask is removed and the open area filled in with
a second glaze, using a bulb syringe
with a needle applicator.
original inlay was a thin ribbon which varied in
width from an eighth of an inch to three eighths of an inch.
that nearly fills the entire region which had
contained the line drawing of the original masks. The
structure of this
design shows a central core colored brown, orange and grey, and is surrounded
by green
migrating into blue. The wispy hair-like trailings as the
design fades out fascinate. One can only wonder
at the direction of
movement within the glaze that resulted in that pattern.
zirconium. Its color is the result of the
inclusion of a substantial quantity of copper and cobalt.
Close up Images of the interaction region
Image of the piece
bowl with glaze oribe-woof-black and inlay glaze hiAlk_Z3P_MAl
bowl is ~7 inches in diameter
oxidation firing to cone 10 in an electric kiln
Firing profiles
Up Fire profile cone 10
Down Fire Profile cone 10
Clay body is a grolleg porcelain from Clay Art Center in Tacoma, WA.
glaze composition
Empirical Formula oribe-woof-black :
Na2O 0.03
CaO 0.71
MgO 0.16
ZrO2 0.11
3% cobalt carbonate
Inlay Glaze:
Empirical Formula hiAlk_Z3P_MAl :
Na2O 0.51
CaO 0.35
MgO 0.02
P2O5 0.06
TiO2 0.22