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vince's list/ migration of tin glaze from proto porcelain, 9th=

updated tue 25 jan 11

 

Marcia Selsor on sun 23 jan 11

century

Dear Rick,

I gave a presentation on that at the NCECA in Las Vegas at the session =3D
on single firing. My point as part of this panel, was the historical =3D
need for multiple firings and how that began with tin glaze.
In the late 9th century a battle in Central Asia introduced Persians to =
=3D
Proto-porcelain. The Persians had captured some pieces of =3D
proto-porcelain along with thousands of Chinese Prisoners of War of the =3D
late Tang Dynasty.
The Persian king admired the white surface of the proto-porcelain and =3D
set about to have his chemists develop something similar. Since they had =
=3D
gritty tan lowfire clay, they developed the white opaque (tin) glaze. =3D
Their addition of blue overglaze migrated back to China where the =3D
Chinese began using the blue slip decoration. So that influence worked =3D
both ways. The tin glaze needed to be applied to a bisque because of the =
=3D
impurities of the lowlfire clay contaminating the opaque white glaze. =3D
This later developed into three required firings when they developed =3D
luster ware as well as enamel, Min'ai, in the 10-11th centuries.

Marcia Selsor,=3D20
Professor Emerita, Montana State University, Billings

On Jan 23, 2011, at 2:05 PM, rickmahaffey@COMCAST.NET wrote:

> Vince good list, but if you include #8 you have to include the Chinese =
=3D
potters whose porcelain prompted the that early Middle Eastern potter =3D
(Islam dates from 610CE- not sure but Tin in a lead glaze may predate =3D
Islam) to try to find a way to make his earthenware white to compete and =
=3D
in someway surpass ware from China.
>=3D20
> YMMV,
> Rick Mahaffey
>=3D20

Marcia Selsor
http://www.marciaselsor.com

rickmahaffey@COMCAST.NET on mon 24 jan 11

century

Dear Marcia,=3D20



Thank you for the information!=3DC2=3DA0 I missed your talk at NCECA Las Ve=
gas.=3D
=3DC2=3DA0 I was attending another presentation that was not as informative=
as =3D
yours!=3D20



On the proto porcelain what date to you have for porcelain production in Ch=
=3D
ina?=3DC2=3DA0 Visiting China=3DC2=3DA0I saw Museum =3DC2=3DA0displays=3DC2=
=3DA0indicating =3D
that=3DC2=3DA0=3DC2=3DA0proto porcelain was left behind by about 200 CE for=
the mos=3D
t part.=3DC2=3DA0 What do you consider to be true porcelain?=3DC2=3DA0What =
is true =3D
porcelain and when it was in production is an interesting topic and there s=
=3D
eem to be many differing=3DC2=3DA0opinions about that.=3D20



Rick =3DC2=3DA0=3D20

=3DC2=3DA0=3D20


----- Original Message -----=3D20
From: "Marcia Selsor" =3D20
To: rickmahaffey@COMCAST.NET=3D20
Cc: Clayart@LSV.CERAMICS.ORG=3D20
Sent: Sunday, January 23, 2011 4:18:28 PM=3D20
Subject: Re: Vince's list/ migration of Tin glaze from Proto Porcelain, 9th=
=3D
century=3D20

Dear Rick,=3D20

I gave a presentation on that at the NCECA in Las Vegas at the session on s=
=3D
ingle firing. My point as part of this panel, was the historical need for m=
=3D
ultiple firings and how that began with tin glaze.=3D20
=3DC2=3DA0In the late 9th century a battle in Central Asia introduced Persi=
ans =3D
to Proto-porcelain. The Persians had captured some pieces of proto-porcelai=
=3D
n along with thousands of Chinese Prisoners of War of the late Tang Dynasty=
=3D
.=3D20
The Persian king admired the white surface of the proto-porcelain and set a=
=3D
bout to have his chemists develop something similar. Since they had gritty =
=3D
tan lowfire clay, they developed the white opaque (tin) glaze. Their additi=
=3D
on of blue overglaze migrated back to China where the Chinese began using t=
=3D
he blue slip decoration. =3DC2=3DA0So that influence worked both ways. The =
tin =3D
glaze needed to be applied to a bisque because of the impurities of the low=
=3D
lfire clay contaminating the opaque white glaze. This later developed into =
=3D
three required firings when they developed luster ware as well as enamel, M=
=3D
in'ai, in the 10-11th centuries.=3D20

Marcia =3DC2=3DA0Selsor,=3D20
Professor Emerita, Montana State University, Billings=3D20

On Jan 23, 2011, at 2:05 PM, rickmahaffey@COMCAST.NET wrote:=3D20

> Vince good list, but if you include #8 you have to include the Chinese po=
=3D
tters whose porcelain prompted the that early Middle Eastern potter (Islam =
=3D
dates from 610CE- not sure but Tin in a lead glaze may predate Islam) to tr=
=3D
y to find a way to make his earthenware white to compete and in someway sur=
=3D
pass ware from China.=3D20
>=3D20
> YMMV,=3D20
> Rick Mahaffey=3D20
>=3D20

Marcia Selsor=3D20
http://www.marciaselsor.com=3D20