EGYPTIAN PASTE
Miscellaneous
- Family: None
- Region: None
- Mined At: Unspecified
- Raw Mineral: Yes
- Generic: No
Notes
(Richard Willis)
A self-glazing, low-firing clay body essentially of sand, clay, potash feldspar and soda ash.
Egyptian paste was used by the ancient Egyptians possibly as far back as 7,000 years, as attested by ornaments made from this material found in burial tombs.
The paste contains soluble salts that rise to the surface while it is drying. This layer of salt fluxes the surface and also lowers vitrifying temperatures. Careful handling is needed to not brush away the crystalline surface before firing. Slow and even drying will aid a consistent sodium coverage and its evenly glazed effect.
Because the paste glazes all-over the formed pieces must be fired sitting on stilts or strung on wires. The “clay” is short, with little elasticity, and thus not very suitable for fast wheel throwing; though some modern Egyptian Paste recipes are indeed devised for fast wheel throwing.
Any colorants suitable for other types of “salt glazing” can be used successfully. The most traditional colorants, that gave the characteristic “Egyptian turquoise”, are oxides and carbonates of copper. The normal firing range is 900ºC - 1000ºC, cone 010 - 06.
modern recipes in dry-weight parts, for base glazes at cone 010 - 06
— soda feldspar 39.0, silica 12.0, ball clay 6.0, soda ash 6.0, sodium bicarbonate 39.0
— soda feldspar 35.0, silica 12.0, ball clay/china clay 2.0, bentonite 6.0, soda bicarbonate 6.0, sodium carbonate 35.0
—— plus 3% oxides or carbonates for coloring
more elastic body at cone 08 - 06
— ball clay 25.0, nepheline syenite 15.0, boro-silicate frit 20.0, silica 5.0, fine sand 3.0, calcined borax 4.0, soda ash 3.0, bentonite 25.0
Authors
- Richard Willis (Owner)
XML
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<material name="EGYPTIAN PASTE" descrip="" generic="0" rawmineral="1" searchkey="" loi="0.00">
<notes>
<note>A self-glazing, low-firing clay body essentially of sand, clay, potash feldspar and soda ash.<BR>
Egyptian paste was used by the ancient Egyptians possibly as far back as 7,000 years, as attested by ornaments made from this material found in burial tombs.<BR>
The paste contains soluble salts that rise to the surface while it is drying. This layer of salt fluxes the surface and also lowers vitrifying temperatures. Careful handling is needed to not brush away the crystalline surface before firing. Slow and even drying will aid a consistent sodium coverage and its evenly glazed effect.<BR>
Because the paste glazes all-over the formed pieces must be fired sitting on stilts or strung on wires. The &#147;clay&#148; is short, with little elasticity, and thus not very suitable for fast wheel throwing; though some modern Egyptian Paste recipes are indeed devised for fast wheel throwing.<BR>
Any colorants suitable for other types of &#147;salt glazing&#148; can be used successfully. The most traditional colorants, that gave the characteristic &#147;Egyptian turquoise&#148;, are oxides and carbonates of copper. The normal firing range is 900&ordm;C - 1000&ordm;C, cone 010 - 06.<BR>
<B>modern recipes</B> in dry-weight parts, for base glazes at cone 010 - 06<B><BR>
</B>&#151; soda feldspar 39.0, silica 12.0, ball clay 6.0, soda ash 6.0, sodium bicarbonate 39.0<BR>
&#151; soda feldspar 35.0, silica 12.0, ball clay/china clay 2.0, bentonite 6.0, soda bicarbonate 6.0, sodium carbonate 35.0<BR>
&#151;&#151; plus 3% oxides or carbonates for coloring<BR>
<B>more elastic body at cone 08 - 06<BR>
</B>&#151; ball clay 25.0, nepheline syenite 15.0, boro-silicate frit 20.0, silica 5.0, fine sand 3.0, calcined borax 4.0, soda ash 3.0, bentonite 25.0<BR>
</note>
</notes>
</material>
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