Substituting MgO for BaO in a matte will also make a matte, right? Wrong.

Thursday 2nd October 2014

Left: G2934 magnesia cone 6 matte (sold by Plainsman Clays). Right (G2934D): The same glaze, but with 0.4 molar of BaO (from Ferro Frit CC-257) substituted for the 0.4 MgO it had. The MgO is the mechanism of the matte effect. Barium also creates mattes, but only if the chemistry of the host glaze and the temperature are right. In addition, barium mattes are normally made using the raw carbonate form, not a frit. In fritted form, barium can be a powerful flux when well dissolved in the melt and boron is present. This glaze is actually remarkably transparent. However, if this was fired lower it could very well matte.

Pages that reference this post in the Digitalfire Reference Database:

Concentrate on One Good Glaze, Ferro Frit CC-257, BaO, G2934 - Matte Glaze Base for Cone 6

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