This section is intended to provide information for purchasers of sculpture created by group members.

It details some of the more common media used in constructing sculpture, provides a brief guide to some of the terminology encountered, and offers a comprehensive to guide to care and maintenance of the various types of sculpture.

Types of media


Stone:  Many different types of stone may be carved to make sculpture.  Stone carvings are unique pieces of work requiring skill and hard work to produce.

Wood:  Woods vary in colour, density and texture.  Some are easier to work than others and skill is required to bring out the unique characteristics of both the wood and the design.

Metal: Any metal can be used to create sculptures, including iron, steel, stainless steel, bronze, copper etc. Each metal has different characteristics and requires varying techniques to work. Some sculptors combine various metals into a single sculpture.

Foundry Bronze:  This is molten bronze metal (an alloy of copper and tin).  It is poured into a specially prepared mould by skilled foundry workers.  The artist will have made the original sculpture in a different material eg, clay or plaster and the mould will have been made on that original.  Bronze is heavy, durable and expensive because of the number of processes and workers involved in it’s production.  The artist will choose the final colour of the patination and oversee the finishing processes.

Bronze resin:  An alternative to expensive foundry bronze, resin is a mixture of real powdered bronze and polyester resin.  It is laid into a prepared mould and strengthened with other materials such as fibreglass.   Since no heat is required for this process it is often done in the studio by the sculptor or by a technician.  It is patinated in a similar way to foundry bronze and can look identical, but is much lighter in weight.

Other resins:  Polyester and other resin can be used to bind many types of inert material.  Ground marble and other stones, different metals, larger particles such as gravel or grit, and/or coloured pigments may be included.  Clear resins may be used to create works with the appearance of glass.

Clay:  There are many different types of clay, a most versatile sculptural material.  It can be used to model the original from which a mould is to be made for casting.  It is also used to make original works for firing to high temperatures in a kiln to produce:  terracotta, generally as an unglazed item;  stoneware, which is fired to a much higher temperature thus making it stronger and harder; ceramic,  glazed earthenware or stoneware and porcelain,  a very fine clay with other additives, sometimes becoming translucent after firing to stoneware temperature.  There are many other types of fired clay.

Plaster:  Plaster of Paris is most commonly used for sculpture,  a strong pure white, fine textured powder mixed with water, which is fast setting and can be coloured as desired.  It may be used to make original works of art, or as a construction material for the making of moulds.  It is not waterproof and therefore not suitable for outdoor sculpture.

Cement:  Cement is a weatherproof material often used for outdoor sculpture.  It can be cast in a mould or modelled directly on to a supporting structure.   It can be coloured by including pigments into the wet mixture or patinated by application of paints etc. to the finished surface.  A very fast setting dark  coloured cement, ciment fondu is frequently used for casting.  Portland cement is the ubiquitous grey one used by builders to make concrete, it takes longer to set.  White cement is sold under various trade names and is pure white.  It takes longer to fully harden after casting.

Papier mache:  This is made from paper and glue often with incorporated items such as wood, fabric and plant materials.  Very large, lightweight and extremely strong structures can be made in papier mache.  This material is not suitable for outdoor display because it is not weatherproof.

Computer-aided manufacturing:  This is a relatively new technique, which allows a sculptor who is skilled in the use of Computer-Aided Design systems to develop work using computer software, and then have it realised using a computer-controlled cutting or manufacturing machine. The result may then be plated or otherwise finished by hand, if desired. Materials available now range from various robust plastics and resins, through conventional metals, and on to precious metals.

There is no limit to the range of materials that can be used to create sculptures. Each artist will find a medium that allows them to express their ideas in a way that satisfies them. The Oxford Sculptors Group encourages people to experiment and explore materials until they find one, or a combination, that suits them.

Terminology

The Dictionary defines sculpture as:


1. The art of making figures or designs in relief or in the round by carving, modelling etc. or casting metals etc.
2.  Works, or a work made in this way.
3.  Ridges or indentations, as on a shell, made by natural processes.

 

Sculpture can be anything that is three-dimensional which has been made for the purpose of observation and/or tactile sensation.  Here is a brief guide to some of the methods commonly used:

Carving: the cutting away of wood, stone etc. to produce a shape which is unique in it’s original material.

Modelling:  The building up of a shape in clay, plaster, wax, papier-mache etc to make a work which may then require other processes (eg firing or casting) to turn it into a stable material.

Moulding:  Making a mould on a piece of original art so that it can be duplicated in various materials to make copies.

Casting:  The process of making a copy of a work in a mould, either in a foundry (for molten metals) or in the studio, by the use of resins, cements, plasters etc.

Firing: Heating clay in a kiln to produce a permanent material.

Patination:  Treatment of the surface of a finished work with chemicals, waxes etc. for colouration and texture.

Mixed media:  A sculpture made up of two or more different materials (eg, wood and stone).

Collage and construction:  An assemblage of joined ‘found items’.

Care and maintenance


Original and Unique Stone Sculptures
Stone sculptures, for example those carved from stones such as Portland, Bath and Lincolnshire limestone, or marble, are normally suitable for permanent outdoor display. Others such as soapstone and alabaster are not.

As far as maintenance is concerned, many people prefer to leave their outdoor sculptures to attract lichens and other natural colourings. The natural patina that develops over time can be very attractive and add character to the sculpture. If you do want to attempt to maintain the sculpture's original appearance, it can usually be cleaned with a cloth or soft brush and water. If the dirt or discolouration is severe, a little bleach could be used as long as this is thoroughly rinsed away afterwards, but it would be best to try this on an unseen area of the sculpture first. Cleaning the sculpture too regularly may begin to spoil the surface. If you feel the sculpture needs more attention, contact the artist who will usually be willing to provide advice and may be in a position to clean the sculpture for you at an agreed cost.

The artist will always take great care to select materials that are totally free from defects and most sculptures can live outdoors for many years without any serious degradation. But stone is a natural product and imperfections; even in the case of stone sculptures normally regarded as suitable for outside display, can occasionally exist. Such imperfections may be of no significance, or may never reveal themselves. In warmer climates there are generally no problems associated with having stone sculptures outdoors. In colder climates, winter temperatures that drop below zero for a sustained period are generally too cold for sculptures outside as they may absorb moisture, freeze and then crack. In such circumstances you should  try to raise the sculpture off the ground to prevent moisture being absorbed and as an extra precaution apply a concrete/driveway sealer to the underside of the base. In extremely cold areas it is recommended that you bring them inside for the Winter if possible.

Bear in mind that even seemingly disastrous breakages can sometimes be made good, so contact the sculptor for advice.

Ceramic Sculptures

Much of what has been said about stone sculptures applies to ceramic sculptures. If a ceramic sculpture has no glaze applied then generally people would allow it to develop its own character. If a glaze is applied, it will be easier to keep it in a condition closer to its original using the same techniques described above.

The artist will make it clear whether their sculptures are suitable for all weather outdoor display, whether it is advisable to take them inside during the winter, or whether they are for inside display only.

Metal Sculptures
As with other sculptures a buyer must decide the extent to which they expect their sculpture to retain its ‘as new’ appearance. Some metal sculptures are designed to develop a weathered appearance. In the case of iron and steel, that may be a natural rust, which can greatly enhance the sculpture’s impact. In the case of copper, for instance, left to itself it will develop a natural verdigri, which can be very attractive.

Some metal sculptures are treated with a varnish finish, which will often last for 5 years, or so, but if the buyer wishes to keep the original appearance of the sculpture, it will be necessary to clean and recoat the sculpture occasionally. However, most buyers are content to allow the sculpture to develop in its own way.

Bronze sculptures will, of course, normally be left to patinate naturally.

Bronze, White Marble and other resin editions
Sculpture editions are usually made using materials such as bronze or white marble resin. Other materials can be used. For example, pure bronze.

A bronze resin edition is made by creating a mould of the original sculpture and then filling the outer skin of the mould with powdered bronze mixed with (normally) polyester resin. The resulting edition is often of lighter weight than the original sculpture but is extremely strong and durable. It can be patinated to produce the same kind of effects one would see with real bronze and with time it will develop even more character in a similar way to real bronze.

Please note that this information is based on material originally compiled by Jeanne Argent, to whom thanks are due.