Iron Colors
satIron_ZG_Z3N , at cone 11.5 is a lovely, variegated oil spot glaze, which
is thin on the rim as a result of
Here it is seen at cone 10, thought with a thick application and an embedded
leaf. The heavy pitting
The leaf in this case is buried is the volcanic action of the glaze. This
slightly underfired glaze,
The leaf wash contains phosphorus. The leaf itself is first softened in water,
containing trisodium phosphate,
After the pot is glazed, the softened leaf is pressed into the glaze.
When the glaze dries, a swatch of plate
Several closeups of the surface of the glaze, including images of the
interaction between the glaze
plate is ~ 7 inches in diameter
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 1900 deg F then a 2 hour hold at 1900 deg F
300 deg F an hour to 1750 deg F then a 1 hour hold at 1750 deg F
300 deg F an hour to 1700 deg F then a 3 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 0.15
Al2O3 0.72
SiO2 3.58
molecular percent Silica 63.79%
K2O 0.43
Al2O3 0.54
SiO2 3.33
molecular percent Silica 48%
low viscosity.
and many only partially healed bubbles are the
result of a lower firing temperature and the thick
glaze application
which is so favorable to interesting leaf prints.
not yet fully homogenized, exhibits a range of
iron colors not otherwise easily seen. Elements of the
embedded leaf are
discernable with close examination.
which provides additional color.
including the leaf is coated with wax.
When the wax is dry, the leaf is removed and the indentations in the
glaze are coated with a very thin layer of an underfired glaze, leaf_Z3K.
and the wash over the leaf embedded in the
glaze are shown. A picture of the plate is also shown.
Images of the surface and its interaction with the leaf wash
Image of the glaze satIron_ZG_Z3N with leaf wash leaf_Z3K
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 composition
Background Glaze:
Empirical Formula satIron_ZG_Z3N:
Na2O 0.55
CaO 0.27
MgO 0.03
Fe2O3 0.24
P2O5 0.07
Empirical Formulae of leaf wash glaze leaf_Z3K:
Na2O 0.53
CaO 0.04
P2O5 0.15