Pottery is one of the most ancient forms of art that is still continued today.
The art-form refers to a process by which items such as bowls, plates, vases, and pots are created from clay which is molded into a vessel and hardened by the addition of heat. To create modern pottery, several different techniques are used, each of which has a massive impact on the final product. The three stages of pottery include the creation, in which the piece is made from the soft, pliable clay; the finishing, when the piece is hardened through different heating processes; and the glazing stage, where decorative colour and water-resistant sealing is added.
Creation Techniques
The pottery wheel is the most popular technique used by artists today. The wheel can be spun by an electric motor or manually powered by the potter’s foot. The wheel itself is a circular stone or wood slab which spins, allowing the potter to form and shape a symmetrical vessel out of a lump of clay using centrifugal force. Various wooden tools and wires can aid an artist as they create their piece. Hands are coated in water and slip (clay which is mixed with water until it becomes muddy) to allow the clay of the pot to slip through the artist’s hands. Pressure is applied through the palms and fingertips to shape the pot (1).
The other technique, used by more traditional potters, and among the first methods of pottery, is hand-building. As the name describes, hand-building does not involve a wheel, but instead is formed solely by use of the hands. Artists will manually shape and create pots either from a solid block of clay, or by “coiling” which is a term that describes building a pot layer by layer with hand-rolled coils of clay. The coils are stacked and blended together helping to achieve a more symmetrical vessel.
Glazing Techniques
After the building process is complete and the artist has finished forming the pottery into the desired shape and added any design imprints into the clay, it must be set aside to dry. Once dried, a raw piece of clay is brittle and porous, meaning it will absorb any liquids that are placed in to it. To create usable pieces, a potter must glaze and fire the item to complete it. There are several different techniques used by potters to decorate and protect their creations.
Dip pots are used when a piece only requires a single colour. Using a container filled with the desired glaze, the piece of pottery is dipped directly into the glaze, which gives it a consistent, uniformed coat everywhere but the bottom where it will come in contact with the shelves of the kiln. Glaze can also be applied with a sponge or brush, much like paint. The unfired glaze is usually dull and lackluster, and may appear a different colour than the final product. Once fired, the glaze takes on its intended colour and depending on the type, has a matte or shined exterior (2).
Firing Techniques
Firing is an essential component to pottery and the temperature of the firing greatly affects the outcome of the piece. Today, pottery is heated in a specialized oven called a kiln, which is designed to carefully temper the items without scorching the surface.
There are two different types of firing, and each piece must be appropriately heated for the best results. The temperature of a kiln is measured by cones, which are placed in the heat with the pieces to carefully monitor the intensity. Low fire, which is usually classified as cone 4, is heated around 1,950 degrees Fahrenheit. Low fire is best for pottery that is brightly coloured, as the substances used in the creation of the glazes is more susceptible to discolouration at higher heat. Low fire is also encouraged for pieces which have intricate designs carved in to the clay, as the lower temperatures allow the glaze to lay over the embedded design (4).
High firing is more often used for pieces which require better waterproofing, such as vases and ceramics. High firing is usually achieved at a cone 10, or 2,380 degrees Fahrenheit. High heat creates a stronger, tighter vitrification, which is achieved as the clay fuses permanently together, holding the final form. Low fire does not fully bond the clay, meaning the pieces are more fragile than the heartier high fire earthenware. According to award-winning potter Scott Schaffer, high firing produces a glass-like exterior appearance and the strongest, most durable finish (3).
Pottery is a delicate, discerning craft where care and experience make for the best finished product. From the selection of glazes, to the different building techniques, and the differences in firing temperatures, each choice greatly affects the intended outcome and makes each piece unique.
Sources:
- wiseGEEK, “What Are the Different Types of Pottery Techniques?,” http://www.wisegeek.com/what-are-the-different-types-of-pottery-techniques.htm
- About.com, “Techniques Used to Create Interesting Pottery,” http://pottery.about.com/od/decoratingtechniques/u/userpath2.htm
- Anne Thull, “Scott Shaffer Hand-Crafted Pottery,” http://annethullfineartdesigns.com/artists/scott-shaffer/#biography
- Lakeside Pottery, “Heatwork Chart: Transformation of Ceramic Materials by Heat,” http://www.lakesidepottery.com/HTML%20Text/Tips/Tempruturerange.htm
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