glaze class // line blend / manganese + rutile

This lesson we made line blends, the purpose of this line blend was to test the effect that glaze colourants play in the glaze mix. Line blends consist of ascending and descending ratios of 2 different ingredients, in this case, colouring oxides.

This test was done on JB3 stoneware clay, and the glaze recipe used was-

Bernard Leach base glaze  – 40/30/20/10

potash feldspar 40

silica 30

whiting 20

kaolin 10

with the addition of manganese dioxide and rutile.

We mix up 2 x 100 grams batches of the base glaze, in 2 separate plastic cups, and add to the first cup add 5% manganese dioxide (Mn) colourant to the base glaze, and to the second cup add 10% rutile (Ru) to the base glaze. So we end up with 2 cups with 2 different colourant in each glaze.

The left hand side, tile 1, starts with the 100% manganese glaze recipe, and the right hand side, tile 11, with the 100% rutile glaze recipe, then you work from left to right, tile 2 equals 9 parts manganese recipe to 1 part rutile recipe, tile 3 equals 8 parts manganese recipe to 2 parts rutile recipe, and so on.

After firing to cone 9, one set in reduction, one set in oxidation, the results where pretty nice. I liked the Bernard leach base it has a low gloss sheen to it, smooth to touch, and I also liked the effect of rutile (titanium) suspended in the glaze. The colours varied from transparent brown, purple/blue, tan, beige in oxidation, to transparent green, tan, beige and slight opaque green in reduction. I lean towards liking the rutile end more.

by the way ignore my mistake of writing Mg instead of Mn on the reduction tiles. Mg stands for magnesium, Mn stands for manganese.


About MOUNTAINpottery

Mountain Pottery is designed and handmade by Deanne Sarita Smart. The studio is located in a small town of Sassafras in the Mountains of Australia. This pottery is made to be collected, loved and used everyday as some of your most treasured belongings. Each piece is unique and made to order. Aside from being beautiful and functional objects, each collection has an underlying meaning, message or intention. All the vessels are inspired in some way by myth, nature, and symbolic language. About this blog // This blog is designed to be a place of inspiration to others with the same interests and point of view, as well as a look into the creation of Mountain Pottery.

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