gczop
Full Member
Posts: 202
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Yohen
Nov 14, 2015 10:05:49 GMT -6
Post by gczop on Nov 14, 2015 10:05:49 GMT -6
"...only four examples are known in the world." "The best example is in the Seikado Library in Tokyo" "...their Japanese name, Yohen , suggests a changing and glittering brilliance", pg151 Nigel Wood's Chinese Glazes The book does not have a photo, but here is one of the piece in Seikado.  |
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Yohen
Nov 14, 2015 19:00:26 GMT -6
Post by evan cornish-keefe on Nov 14, 2015 19:00:26 GMT -6
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Yohen
Nov 14, 2015 19:21:15 GMT -6
Post by tileman2 on Nov 14, 2015 19:21:15 GMT -6
Never ceases to amaze me; all the information available at a click of a button. Good article.
Tom
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gczop
Full Member
Posts: 202
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Yohen
Nov 14, 2015 21:06:04 GMT -6
Post by gczop on Nov 14, 2015 21:06:04 GMT -6
The paper (Evan's Link) explains that the Jianware oil spot, that is silvery spots on a black glaze, is a crystalline ε-Fe2O3 and that 1-2% oxygen (i.e. reducing atmosphere) is necessary to reliably create them. John Britt's article Oil Spot Glazes says "The most important factor in obtaining oil spot glazes is firing in an oxidation atmosphere." Sanders (Glazes for Special Effects) wrote "contrary to some potters' insistence that a reduction fire is necessary for oil spot development, I have found that oil spot glazes of a superior quality can be produced....in an oxidizing atmosphere."
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Yohen
Nov 16, 2015 11:23:39 GMT -6
Post by evan cornish-keefe on Nov 16, 2015 11:23:39 GMT -6
Hey Gordon,
pg 149 in the book by Nigel Woods mentions the effects of reduction on Jian ware glazes
Sanders uses Jordan clay (low iron), and John Britt uses different porcelains, I wonder whether that might be a significant difference when comparing the effects reduction has with iron rich Jian ware clay?
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gczop
Full Member
Posts: 202
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Yohen
Nov 17, 2015 8:36:09 GMT -6
Post by gczop on Nov 17, 2015 8:36:09 GMT -6
Thanks for the tip Evan, also read under the photo of the Jian Bowl pg 147 talking about a neutral atmosphere. I've been using an albany slip substitute (some RIO added) on first and a black Ding type glaze over it (on porcelain). Until now oxidizing in an electric kiln.
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Yohen
Feb 3, 2016 10:29:32 GMT -6
Post by evan cornish-keefe on Feb 3, 2016 10:29:32 GMT -6
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