What is a pot?

 What is a pot?

• What is a pot?

Most of the work that you see in The Ottawa Guild of Potters sale is ceramic formed from moist clay either thrown on a potter's wheel or hand built.

• How hot does the clay get when fired?

Once the clay is dry, the piece is often bisque fired in a kiln to reduce its fragility, to a temperature of about 1850oF. Glazes, slips and engobes are applied in liquid form in many different compositions to obtain the characteristics and colours desired. A final firing takes the clay to maturity temperatures ranging from 2245oF (cone 6 stoneware) to 2345oF (cone 9), or higher for porcelainsand certain stoneware, produces the finishes that you see on the pieces you see in the various stands.

• Why is a pot the shape it is?

Pots that are formed on the wheel start off as round forms and then may be altered by the potter for the desired shape. Other artists form their pieces using slabs, thin coils or simply pinching so that they can obtain different and often unusual shapes.

• What is raku?

Originally used for tea bowls in the Japanese tea ceremony, the raku process in North America begins with a bisque firing of a clay body with a lot of grog (sometimes prefired clay particles) to provide shock resistance. The pot is decorated with slips or glazes, and then fired to a low temperature in a gas raku kiln out of doors. The artisan waits until the pot is glowing hot and the glazes have melted, around 1600oF, and then removes the glowing hot pieces by tongs from the kiln and quickly places them on some combustible materials in a metal container and closes the lid. The results are unique- sometimes creating iridescent, and metallic effects or crackled finishes on blackened clay. These pots are not meant for use with foods.

• What are the characteristics of a good teapot?

Functional teapots have comfortable and solid handles, are well-balanced so that they are easy to lift and pour well. The lids remain in place when pouring. The lip of the spout should be higher than the liquid inside so that the tea doesn't spill out the top of a full pot when it is poured. Their pleasing appearance may be what attracts you.  The skills needed to create good teapots require considerable practice and finesse.

• What do you like about the works you see?

Do you like the shapes, textures, glossy, buttery or matt finish? Does the shape and surface of the piece make you want to pick it up? Are you attracted the applied design? Does the subject matter of sculptural work have an emotional appeal? What doe you like about the shape?

• What is unique about porcelain?

Porcelain is a very white clay that fires to a very high temperature, sometimes having a translucent quality. Coloured glazes applied to porcelain have a vibrancy that is unique to this ware.

• What are the qualities of a good casserole dish?

Casserole dishes need to be tough and handle the change of temperature from cold to hot without cracking. They also should be able to handle microwave and dishwasher treatments without a problem. The clays selected for this type of ware are called stoneware clays. Casseroles also need to have lid and body handles that are big enough to be lifted by oven mitts. Their surfaces should be easy to clean.

• How does a mug feel in your hand?

Before buying a mug, lift it up and feel it. Does it feel light in weight for its size, does the handle fit your hand well? Is the finish smooth to your touch? If you bring the lip to your mouth, would coffee pour out easily? Is it big enough to fill your coffee desires?

• What makes ceramic colours?

Glazes are applied to pots in a watery form. When fired they become thin glass compounds of silica (glass former), alumina (stabilizes the glaze to prevent too much flow) balanced with a flux (which lowers the melting point). These materials and others such as metal compounds determine the colours, texture or smoothness, glassy or matt finishes. For example, the blue found in the decoration of many china plates has cobalt added, a powerful colourant. Copper produces blue-greens and iron produces reds, browns and tans, both in oxidation firing.

• How long does it take to fire a clay pot?

Depending on the temperature required to optimize the hardness of a pot, the firing can take hours ( raku) or several days (wood firing). The clay must be heated slowly over a period to prevent cracking or other defects.

• Can ceramics go into microwave ovens?

Avoid putting ceramics with metallic surfaces such as gold and silver in the microwave. If you are unsure, contact the potter who made the work.

• What is salt or fumed ware?

Salt glazing is a technique used in the 12th century. Salt is introduced into the hot kiln when the pottery has been fired to maturity (optimum temperature). The salt forms a vapour and the sodium combines with the silica on the pot surface to form a thin glaze coating. This process must be done in a well-vented studio in a dedicated kiln .

• What is unique about wood fired pieces?

Wood firing takes pots to a very high temperature at which the wood ash is deposited on the surface of the pottery, creating an attractive textured finish.

• What is the Ottawa Guild of Potters?

The Ottawa Guild of Potters number around 150 members. They hail from the Ottawa-Gatineau regions. Potters have their own unique styles that offer the variety of creative work that you find in our sale and exhibition. Our main events are the twice yearly sale of members work, the juried Spring Exhibition and the ever popular charity event, Great Bowls of Fire, which has raised around $70,000 for the Ottawa food Bank during the six years it has run, through the assistance of dedicated member-volunteers and local restaurants, caterers, bakeries and musicians.

• Where is home for the guild?

The Guild does not have a permanent studio. Monthly meetings occur at the Nepean Visual Arts Centre at 1701 Woodroofe Ave., at the back of the Sportsplex. Many of our members have their own studio, share studio space such as the Gladstone Clay Works, or work in the many teaching facilities run by the City of Ottawa. For more information about the Guild, check out our website at www. ottawaguildofpotters.ca.

• Does the guild have a studio tour?

The Guild has two sales and one exhibition a year, but many members are part of studio tours both within the city centre and in the surrounding region. More information is available on our website at www.ottawaguildofpotters.ca.

by Sandra Marshall