It is one of the more challenging techniques a potter can undertake. Losses can be dramatic and heartbreaking and for this reason Crystalline is considered by many potters too difficult to pursue to any degree.

Porcelain is generally the clay of choice as any impurities in the clay can affect colour and growth of crystals. Due to its lack of body and ability to stand up on the potters’ wheel the use of porcelain clay demands skill, especially on larger pieces.

The specially formulated crystalline glazes require careful application and are fired up to peak temperatures of 1320 Celsius (2400F).

At these high temperatures the glaze is very fluid and has the tendency to flow from the surface of the pot. This fluidity necessitates the pot being attached to an added pedestal and catch basin to contain the glaze runoff. Post firing this catcher is separated from the pot increasing the risk of loss or damage.

Once peak temperatures have been reached the kilns are rapidly cooled to pre-determined temperatures where the crystals are grown. The growth window for crystals is generally within the range of 1000-1100C. As crystal formation requires slow cooling, temperatures are held and manipulated for up to 4-6 hours or more to allow for crystal growth within the glaze matrix.

Crystals are formed at random, can take on a myriad of shapes and are three dimensional in nature. In direct sunlight or strong light, spectacular effects created by the refraction of light bouncing off the crystals give each piece its three dimensional quality and depth. Crystalline is one of the most stunning glaze techniques available.

Metallic oxides and combinations of various materials are used to produce a unique spectrum of colours ranging from cobalt blues through to pinks, browns, red, pearls and reef greens. Glaze formula, phase of melt and availability of materials within the molten glaze along with many other variables all combine to determine the final result.

Like molten lava moving down a mountain side the actual crystals are not present in the flow but grow in pockets where available and conducive materials come together as the lava slowly cools.

The beauty, depth and life expressed in a Crystalline glaze is spectacular and unsurpassed. It is a challenge to even the most experienced and knowledgeable potter.

Mastering and understanding the Crystalline process does not come easily It will test your powers of perseverance, commitment, your bank balance. It will humble you and at times have you question your sanity. Results must be won by many hours of hard work and dedication