A mixture of coloring oxide and water, sometimes including a little flux, used as an overall patina (often on unglazed work) or for overglaze brushwork.
Source:
Clay: A Studio Handbook
Oxidation
Any chemical reaction in which atoms or molecules combine with oxygen atoms. The combustion of fuel is an oxidation reaction.
Source:
Clay: A Studio Handbook
Overspray
In spraying glazes or other mediums, the small droplets and/or dust that do not settle on the object being sprayed. An adequate spray booth is essential in order to exhaust all overspray.
Source:
Clay: A Studio Handbook
Overglaze
Any surface decoration applied over the glaze surface, either as an oxide wash applied over raw glaze surface before glaze-firing, or as a lower-temperature medium fired onto a previously higher-fired glaze surface, as in china paints and lusters.
Source:
Clay: A Studio Handbook
Orifice
In a gas or oil burner, the restricted opening through which a jet of fuel emerges.
Source:
Clay: A Studio Handbook
Opax
Zircon opacifier. Toxic in inhalation.
Source:
Clay: A Studio Handbook
Opacifier
In glaze formulation, a material that produces inert inclusions or minute crystals in glaze, causing it to become opaque. Most common are tin oxide and zirconium silicate.
Source:
Clay: A Studio Handbook
Ocmulgee
Rich golden-brown stoneware clay, no longer being mined.
Source:
Clay: A Studio Handbook
Nuka
An often-iridescent, milky-white Japanese glaze containing rice-hull ash.
Source:
Clay: A Studio Handbook
Noborigama
Translates as “step-climbing kiln”—traditional Japanese multichamber downdraft/crossdraft climbing kiln, with initial firebox at bottom, and secondary fireboxes in each chamber. As kiln is fired, each chamber preheats the next. See climbing kiln.
Source:
Clay: A Studio Handbook
Neutrals
In glaze chemistry, the refractories or stabilizers that are combined with bases (fluxes) and acids (glass-formers).
Source:
Clay: A Studio Handbook
Neutral Atmosphere
In fuel-burning kiln, atmosphere that is neither oxidizing nor reducing—most efficient atmosphere for efficient climb and even temperature.
Source:
Clay: A Studio Handbook
Nc 4 Feldspar
Na2O×Al2O3×6SiO2—soda feldspar, interchangeable with Kona F-4. Toxic in inhalation.
Source:
Clay: A Studio Handbook
Natural Draft
Firing system in a fuel-burning kiln that uses natural convection currents in kiln (updraft) or in chimney (downdraft), without any mechanical blowers, to draw in secondary air, circulate heat and atmosphere through kiln, and exhaust combustion gases.
Source:
Clay: A Studio Handbook
Mullite
3Al2O3×2SiO2—calcined Kyanite, but is also found naturally. Very desirable interlocking needlelike aluminum silicate crystals form above 1800° F and greatly add to the strength of high-fired vitrified clay bodies and glazes. In well-formulated high-fired wares, clay-glaze interface is extremely strong partially due to interlocking mullite crystals.
Source:
Clay: A Studio Handbook
Montmorillonite
Clays such as bentonite, resulting from the breakdown of airborne volcanic ash. The finest particle size of all clays. Very high shrinkage, and generally used only as an additive to clay bodies or glazes.
Source:
Clay: A Studio Handbook
Molecule
A group of atoms chemically bonded together to form a compound.
Source:
Clay: A Studio Handbook
Modifiers
Glaze materials that are added to a base glaze to modify surface qualities such as color, gloss, matteness, opacity, crystal development, etc.
Source:
Clay: A Studio Handbook
Mishima Ceramics
East Asian method of creating an inlaid effect by applying contrasting slip into a design incised in leather-hard clay. When the slip stiffens, the excess is scraped off.
Source:
Clay: A Studio Handbook
Mid Range
Glaze-firing range usually including cone 4 to cone 7, very popular with electric kilns
A mixture of coloring oxide and water, sometimes including a little flux, used as an overall patina (often on unglazed work) or for overglaze brushwork.
Source: Clay: A Studio Handbook
Any chemical reaction in which atoms or molecules combine with oxygen atoms. The combustion of fuel is an oxidation reaction.
Source: Clay: A Studio Handbook
In spraying glazes or other mediums, the small droplets and/or dust that do not settle on the object being sprayed. An adequate spray booth is essential in order to exhaust all overspray.
Source: Clay: A Studio Handbook
Any surface decoration applied over the glaze surface, either as an oxide wash applied over raw glaze surface before glaze-firing, or as a lower-temperature medium fired onto a previously higher-fired glaze surface, as in china paints and lusters.
Source: Clay: A Studio Handbook
Source: Clay: A Studio Handbook
Zircon opacifier. Toxic in inhalation.
Source: Clay: A Studio Handbook
In glaze formulation, a material that produces inert inclusions or minute crystals in glaze, causing it to become opaque. Most common are tin oxide and zirconium silicate.
Source: Clay: A Studio Handbook
Rich golden-brown stoneware clay, no longer being mined.
Source: Clay: A Studio Handbook
An often-iridescent, milky-white Japanese glaze containing rice-hull ash.
Source: Clay: A Studio Handbook
Translates as “step-climbing kiln”—traditional Japanese multichamber downdraft/crossdraft climbing kiln, with initial firebox at bottom, and secondary fireboxes in each chamber. As kiln is fired, each chamber preheats the next. See climbing kiln.
Source: Clay: A Studio Handbook
In glaze chemistry, the refractories or stabilizers that are combined with bases (fluxes) and acids (glass-formers).
Source: Clay: A Studio Handbook
In fuel-burning kiln, atmosphere that is neither oxidizing nor reducing—most efficient atmosphere for efficient climb and even temperature.
Source: Clay: A Studio Handbook
Source: Clay: A Studio Handbook
Firing system in a fuel-burning kiln that uses natural convection currents in kiln (updraft) or in chimney (downdraft), without any mechanical blowers, to draw in secondary air, circulate heat and atmosphere through kiln, and exhaust combustion gases.
Source: Clay: A Studio Handbook
3Al2O3×2SiO2—calcined Kyanite, but is also found naturally. Very desirable interlocking needlelike aluminum silicate crystals form above 1800° F and greatly add to the strength of high-fired vitrified clay bodies and glazes. In well-formulated high-fired wares, clay-glaze interface is extremely strong partially due to interlocking mullite crystals.
Source: Clay: A Studio Handbook
Clays such as bentonite, resulting from the breakdown of airborne volcanic ash. The finest particle size of all clays. Very high shrinkage, and generally used only as an additive to clay bodies or glazes.
Source: Clay: A Studio Handbook
Source: Clay: A Studio Handbook
Glaze materials that are added to a base glaze to modify surface qualities such as color, gloss, matteness, opacity, crystal development, etc.
Source: Clay: A Studio Handbook
East Asian method of creating an inlaid effect by applying contrasting slip into a design incised in leather-hard clay. When the slip stiffens, the excess is scraped off.
Source: Clay: A Studio Handbook
Source: Clay: A Studio Handbook