Clay – Paradise on Earth
The element of Earth instils in us a sense of stillness, grounding and a feeling of being connected. The common playground for all living beings on this planet is this planet, we all call home. Nations fight against each other to protect their soil. It is this very soil that we artists have fashioned over the years into statues of gods, goddesses and great men and women of history. Pottery and ceramics have played an essential role in the evolution of human culture since millennia. From prehistoric age vessels to modern roof tiles, to space shuttles, pottery and ceramics are indispensable in ongoing human endeavors.
What is Clay/Pottery/Ceramics all about?
Most of us today are more familiar with sculpting and modeling in a virtual environment or 3D as we know it. Let us hark back to the basics and the most basic and abundant element of Earth. To be more specific, I am referring to clay; the material that makes pottery and ceramics possible and is actually a mixture of several minerals. Clay is naturally occurring aluminum silicate composed primarily of fine-grained minerals and exhibits plasticity (the ability of the clay to take & hold the form that the potter gives it) when mixed with water in certain proportions. When dry, it becomes firm and when fired in a kiln, permanent physical and chemical changes occur, which convert it into a ceramic material. What is this ceramic you ask? Ceramics is the fine art of manipulating clays into hardened shapes. The objects made out of this art form are called ceramics serving as items of highly esthetical form and utilitarian function in homes and offices. Ceramics are made by moistening a mixture of clays, casting it into a shape and firing it to a high temperature. Pottery is nothing but these very ceramic wares made by this process of vitrification.
Processes and Techniques
1. By Hand
The earliest method where pottery is created by hand from coils, slabs and/or balls of clay. While it is slower than wheel-throwing, it offers more control over the size and shape of the earthen wares. Studio potters believe hand-building to be more conducive to create unique works of art. In addition to the potter’s hands tools, including paddles, anvils & ribs, and those specifically for cutting or piercing such as knives, fluting tools and wires are used.
2. The Potter’s Wheel
In a process called “throwing” (from the Old English word thrawan which means to twist or turn), a ball of clay is placed in the center of a turntable, called the wheel-head, which the potter rotates with a stick, with foot power or with a variable-speed electric motor. During this process, the wheel rotates rapidly while the solid ball of soft clay is pressed, squeezed and pulled gently upwards and outwards into a hollow shape. The first step of pressing the rough ball of clay downward and inward into perfect rotational symmetry is called centering – a most important skill to master before the next steps:
3. Granulate Pressing
Here pottery is shaped by pressing clay in a semi-dry and granulated condition in a mould. The clay is pressed into the mould by a porous die through which water is pumped at high pressure. The granulated clay is prepared by spray-drying to produce a fine and free-flowing material having a moisture content of about 5-6%. Also known as dust pressing, it is widely used in the manufacture of ceramic tiles and of plates.
4. Injection Moulding
It’s a shape-forming process adapted for the tableware industry from the method long established for the forming of thermoplastic and some metal components. It has been called Porcelain Injection Moulding, or PIM and is suited to the mass production of complex-shaped articles, one significant advantage of the technique is that it allows the production of a cup, including the handle, in a single process, and thereby eliminates the handle-fixing operation and produces a stronger bond between cup and handle. This technique is not as widely used.
Is often used in the mass production of ceramics and is ideally suited to the making of wares that cannot be formed by other methods of shaping. A slip, made by mixing clay body with water, is poured into a highly absorbent plaster mold. Water from the slip is absorbed into the mould leaving a layer of clay body covering its internal surfaces and taking its internal shape. Excess slip is poured out of the mold, which is then split open and the molded object removed. Slip-casting is widely used in the production of sanitary wares and is also used for making smaller articles, such as intricately detailed figurines.
6. Pressure Casting
Specially developed polymeric materials allow a mould to be subject to application external pressures higher than slip casting in plaster moulds which leads to much faster casting rates and, hence, faster production cycles. Furthermore, the application of high pressure air through the polymeric moulds upon de-moulding the cast means a new casting cycle can be started immediately. This technique was developed in the 1970s for the production of sanitary-ware although, more recently, it has been applied to tableware.
Handmade pottery can be a very gratifying hobby that produces fun and satisfying results. For many people it’s an enjoyable release that is created by working an inanimate mound of clay into a beautiful work of art that you made through your artistic abilities. For artists and designers from different disciplines, it offers a new medium and an opportunity to tune oneself with a sense we rarely use as digital artists; touch! The best way of starting out is to take a few lessons. You will probably waste quite a bit in materials when you first get started. Figuring out how to truly make handmade pottery correctly and shape into what you want it to be can be quite an ordeal. The different tools available will appear to be a daunting, but once you get set up, just have fun while you’re at it. You can choose to get serious and commence commercial operations, selling creations at craft fairs and small stores or just create items for yourselves, family, relatives, and friends.
Clay Care 101
Tools of the Trade
Sticks, hessian, buttons, garlic press, rolling pin, pastry cutter, spatula, nails, straws, ice block sticks, shells, beads, string, bottle tops, old knives, etc.
Bisque – fired unglazed pottery
Slip Joining – the process used to join two pieces of clay by moistening both pieces with water, making a slip, then pressing firmly together and smoothing the join.
Wedge – the process used to remove any air pockets from the clay prior to modeling.
Fire – the process by which the clay is hardened.
Kiln – the medium used to fire the clay.
Glaze – colour applied to clay after the first (bisque) firing