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Internationally acclaimed ceramic artists Rod & Denyse Simair have represented Canada in major exhibitions in Europe and North America. They are the recipients of the highest international honour that has been awarded exclusively for Crystalline, Le Grand Prix du Jury, at Crystallines 2005 in France. The Simairs combine their talents with Rod's elegant and masterfully thrown original porcelain designs harmoniously brought to fruition through Denyse's personally researched, formulated and fired macro-crystalline glazes. They describe their pieces as "heirloom keepsakes of aesthetically inspiring ceramic art to cherish now and for generations to come".
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This award-winning couple are-all in on crystal glazes. They have learned that success is about data. A lot of data. Thousands of pictures, hundreds of firing schedules, hundreds of recipes, endless notes all come together in the growth of crystals like these! Notice the clear background, no micro-crystals fogging it up. Notice that two fundamentally different types of crystals are being grown. Not to be ignored is the throwing skill it takes to make a porcelain piece like this, these are not small pieces.
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Closeup of a crystalline glaze. Crystals of this type can grow very large (centimeters) in size. These grow because the chemistry of the glaze and the firing have been tuned to encourage them. This involves melts that are highly fluid (lots of fluxes) with added metal oxides and a catalyst. Typically, the fluxes are dominated by K2O and Na2O (from frits) and the catalyst is zinc oxide (enough to contribute a lot of ZnO). Because Al2O3 stiffens glaze melts, preventing crystal growth, it can be almost zero in these glazes (clays and feldspars supply Al2O3, so these glazes have almost none or either of them). The firing cycles involve rapid descents, holds and slow cools (sometimes with rises between them). Each discontinuity in the cooling curve creates specific effects in the crystal growth. These kinds of glazes are within the reach of almost anyone today since electronic controller-equipped kilns are now commodity items - one can fiddle with the chemistry and manage the testing of glazes in their insight-live.com account. But be ready for work, others on this path have done hundreds of firings to perfect a recipe and scedule.
URLs |
https://www.simair.ca/
Rod and Denyse Simair - Crystalline glazes |
Glossary |
Crystalline glazes
A type of ceramic glaze made by potters. Giant multicolored crystals grown on a super gloss low alumina glaze by controlling multiple holds and soaks during cooling |
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