Media & Materials
Sculptors who work in clay have a wide range of options. Terra Cotta is a natural, earth and water clay long favored by classical artists. Drying and firing of the clay results in shrinkage and other structural changes. The types of armatures that can be used for terra cotta sculptures is limited by the need for firing. Most internal armatures will expand and destroy the piece inside the kiln. Terra cotta is a beautiful clay for loosely constructed works, but can be a difficult material for complex, finely detailed, anatomically accurate works.
Many synthetic clays are available. These generally fall into two classes: oil-based and wax-based. Oil-based clays are similar to earthy clays, but with the water replaced by linseed or other oils. Wax-based clays are basically low melting point waxes. The wax-based clays have the advantage of being structurally sound and holding fine detail. They are rigid enough that form is accurately preserved during subsequent mold making. However, the clay must be kept warm while it is being worked, and sculpting is a combination of forming and carving.
Bronze is an ancient material, the choice for cast sculptures for thousands of years. At its simplest, it is an alloy of copper and tin. Modern alloys also include silicon in the mix.
Bronze is very resistant to corrosion, so it is suitable for outdoor sculptures. It naturally oxidizes to a rich warm black in some environments, and to a copper green in others. This surface oxide serves to protect the underlying metal from damage.
The melting point of bronze is about 950°C, which is too high for most direct molding methods. Sculptures are usually cast using the ancient lost-wax technique, which involves making wax replicas of the original from a soft mold, then making sacrificial ceramic molds around the waxes. These molds are fired, leaving a hollow cavity when the wax runs out. Bronze can now be poured into this cavity, and the mold broken away.
Visit here for a description of the process of converting a clay sculpture to bronze.
Pewter is an alloy of tin. It has long been favored for casting because of its relative low cost and its low melting point, 230°C. More expensive pewter intended for eating utensils is normally tin alloyed with copper. Less expensive pewters were traditionally alloyed with lead, but recently antimony or bismuth have been used to replace lead. All of the pewter sculptures available here are made from lead-free alloys.
Pound for pound, pewter is about as expensive as bronze. Finished pieces are much less expensive, however, because pewter can be cast directly in silicone molds, and doesn't require the much more complex lost-wax method.
Natural stone is the most ancient of sculptural materials. Sculpting in stone is a subtractive process, where material is removed until the final form is achieved. Only a small number of sculptors still work in stone. Fortunately, there are materials that allow stone-like casts to be made from originals produced in clay. These can be as simple as plaster or cement, often filled with glass fibers for additional strength. All of Louise's cast stone pieces are molded from a resin heavily fortified with powder from marble or other stone. The resulting material looks and feels very much like natural stone, and is very resistant to UV, making it suitable for outdoor use.