PQotW: Week 26

[Pres]

Week 26

 

1. In stoneware glazes, _____________ is often used as a matting agent giving some excellent opaque matt glazes. It is also very useful in helping to reduce crazing.

   1. calcium

   2. lime alkali

   3. zinc

   4. magnesia

2. _______________ in glazes is due to the refraction and diffusion of light rays reflected from a surface that is minutely rough.

   1. Crystals

   2. Glossiness

   3. Mattness

   4. Durability

3. A rust colored iron glaze-the rion oside crystals arte not visible to the naked eye. The name, _________, is Japanese for “persimmon”.

   1. Temmoku

   2. Tesha

   3. Shino

   4. Kaki

4. The Mino area of Japan was responsible for four distinctive traditional styles of pottery, namely Oribe, Black Seto, Yellow Seto, and ___________

   1. Temmoku

   2. Tesha

   3. Shino

   4. Kaki

 

This weeks questions come from Stoneware Glazes, A Systematic Approach, by Ian Currie, c. 1985 second edition 1986, Bootstrap Pres, Queensland Australia.

 

Note from Pres: I have had this book for many years, read it sporadically, as it is filled with many graphs and triaxial blend images that I have not understood until recently. It was written as a textbook, and is quite detailed in pursuit of the science of Stoneware glazes.

 

 

Answers:

1. 4. Magnesia-ln stoneware glazes, magnesia (Mg0) is often used as a matting agent, giving some excellent opaque malt glazes. It is also very useful in helping to reduce crazing, though the amount used is usually much less than the 0.5 M.P. used in the Magnesium Set here. Interesting color responses are achieved with cobalt and iron oxide pigments. In glazes fairly low in alumina and containing about 0.2 M.P. MgO, a pleasant speckle of pyroxene crystals is fairly easily produced. In an iron glaze, this gives the ‘teadust' effect.

2. 3. Mattness-Mattness in glazes is due to the refraction and diffusion of light rays reflected from a surface that is minutely rough. This roughness may be caused by tiny crystals, undissolved materials, or by mechanical abrasion (e.g. sand blasting), or chemical corrosion (e.g. with hydrofluoric acid) or by bubble effects, or sometimes by minute crinkling of the glaze surface as it cools.

3. 4. Kaki-Kaki - A rust colored iron glaze-the iron oxide crystals are not visible to the naked eye. The name is Japanese for ‘persimmon’.

4. 3. Shino-Although I am primarily concerned here with Shino Ware,it is worth pointing out that the Mino area, where Shino Ware evolved, is also responsible for three other distinctive traditional styles of pottery, namely Oribe, Black Seto and Yellow Seto. The four styles are closely inter- related, and it is fascinating to see how the Mino potters of four hundred years ago created such a wide range of wares from such a narrow range of materials.

[Min]

1 - magnesia

2 - mattness

3 - kaki

4 - shino

Wondering if one of the questions is one of the oops don’t answer to quickly type ones.  Would microcrystalline glazes count as a matt glaze or a crystal glaze? 

Anyhow my best guesses, good questions again, gets me thinking.  

[Judith B]

That's a difficult one this week!

 

1- 4 (I tried to google it but it looks like there are quite a few different elements that can be used for matte glazes, is this the most common?)

2- 3

3- 4

4- 3

[S. Dean]

1. 4

2. 3

3. 4

4. 3

[Chilly]

Whoa,  I must be losing my brain:

 

?
?
?
?

[Babs]

1.1

2. 3

3. 1

4. 3

 

[Denice]

4,3,4,3      I was leaning toward Zinc, it seems like every C6 mat glaze I  use has expensive Zinc oxide in it.   Denice

[LeeU]

3-3-4-3   I have lost track---do the correct answers get posted here or somewhere else? 

[Marcia Selsor]

1, 4

2, 3

3, 4

4, 3