Glazes

Like making, glazing can be addictive for Tessa. She has taken forward and expanded upon her knowledge and in-depth glaze research that was carried out during her Masters at the Royal College of Art. She continually spends time testing numerous glazes in order to produce her expressive ceramic sculptures. She aims for glazes to awaken gratification of the physical senses and selects colours and surfaces for their blending and clashing qualities. Tessa’s glazes enhance the harmony and discord of the sculptural arrangements. Equally through use of rich colourful glaze and three dimensional forms, intensity is embraced, so as to transport the viewer into another dimension. The arousing and soothing qualities of the glazed surfaces reflect the fluidity of human sensations. Through glaze, her sculptures become animated and they provide room for contemplation on impermanent states of existence.

Glaze TestsGlaze tests

Each coloured glaze is made up of a recipe using various balances of mineral constituents. There are vast variations, and accidents can provide for exciting effects, provided they are recorded. Tessa has a glaze archive, some are kindly shared by fellow makers and others are specially developed recipes. The archive is always a work in progress and includes glazes at stoneware and earthenware temperatures, such as lichen/crawls and volcanic/lava/crater/froth glazes. These produce unpredictable effects.

Lichen glaze is named after the growth forms in nature reminiscent of peeling paint. Lichens are also called crawl glazes, a condition that occurs by accident when glaze is applied too thickly, or there is too much water in the mix which causes it to separate into islands when drying. Tessa’s glazes are purposefully intended to crawl and depend on Magnesium Carbonate. MgO has an extremely small particle size which reduces movement, encouraging shrinkage. The islands can be large or small subject to thickness and the angle of the work. Different colours can be produced by layering coloured glazes.

Silicon carbide is necessary to produce erupting glaze surfaces. At certain temperatures, CSi produces a chemical reaction causing gasses to bubble up from under the glaze. Varying the amount will either produce a smooth textured bumpy effect, or a surface filled with large crater like holes that one can see into. Colours can alter within a glaze, especially when oxides are added. Tessa’s carefully recorded glaze recipes inspire and assist with further advancement of work.

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Tessa applies glazes using various methods such as spraying, dipping and pouring, but most typically brushing. Tessa aims to avoid spraying toxic materials into the atmosphere and tends to do this only when pieces have deep internal spaces where she is unable to reach inside. Tessa more often brushes glaze as this allows for different glazes to be applied on a piece and is more economical so that smaller batches can be mixed. Tessa stabilises work in the kiln using stilts that she makes by hand. Work is fired on clay trays to prevent sticking to kiln shelves and adequate space is left between pieces to avoid work sticking together when glaze froths.

Tessa is available to teach glaze workshops. Please get in touch to discuss specifics.