In archaeology and art history, "terracotta" is often used to describe objects such as figurines and loom weights not made on a potter's wheel, with vessels and other objects made on a wheel from the same material referred to as earthenware; the choice of term depends on the type of object rather than the material or shaping technique.
Prior to firing, terracotta clays are easy to shape. Artifacts can be formed by an "additive" technique, adding portions of clay to the growing pieces, or a "subtractive" one, carving into a solid lump with a knife or similar tool. Sometime a combination of these is used: building up the broad shape and then removing or adding more in certain areas to produce details.
After drying, it is placed in a kiln or atop combustible material in a pit, and then fired. The typical firing temperature is around 1,000 °C (1,830 °F), though it may be as low as 600 °C (1,112 °F) in historic and archaeological examples. During this process, the iron content of the clay reacts with oxygen, resulting in the iconic reddish color of terracotta clays. However, the overall color can vary widely, including shades of yellow, orange, buff, red, pink, grey or brown.
A final method is to carve fired bricks or other terracotta shapes. This technique is less common, but examples can be found in the architecture of Bengal on Hindu temples and mosques.
Fired terracotta is not watertight, but its porousness decreases when the body is surface-burnished before firing. A layer of glaze can further decrease permeability and increase watertightness.
Unglazed terracotta is suitable for use below ground to carry pressurized water (an archaic use), for garden pots and irrigation or building decoration in many environments, and for oil containers, oil lamps, or ovens. Most other uses require the material to be glazed, such as tableware, sanitary piping, or building decorations built for freezing environments.
Terracotta will also ring if lightly struck, as long as it is not cracked.
Painted (polychrome) terracotta is typically first covered with a thin coat of gesso, then painted. It is widely used, but only suitable for indoor positions and much less durable than fired colors in or under a ceramic glaze. Terracotta sculptures in the West were rarely left in their "raw" fired state until the 18th century.
Indian sculpture made heavy use of terracotta from as early as the Indus Valley civilization (with stone and metal sculpture being rather rare), and in more sophisticated areas had largely abandoned modeling for using molds by the 1st century BC. This allows relatively large figures, nearly up to life-size, to be made, especially in the Gupta period and the centuries immediately following it. Several vigorous local popular traditions of terracotta folk sculpture remain active today, such as the Bankura horses.
Precolonial West African sculpture also made extensive use of terracotta. The regions most recognized for producing terracotta art in that part of the world include the Nok culture of central and north-central Nigeria, the Ife/Benin cultural axis in western and southern Nigeria (also noted for its exceptionally naturalistic sculpture), and the Igbo culture area of eastern Nigeria, which excelled in terracotta pottery. These related, but separate, traditions also gave birth to elaborate schools of bronze and brass sculpture in the area.
Chinese sculpture made great use of terracotta, with and without glazing and color, from a very early date. The famous Terracotta Army of Emperor Qin Shi Huang, 209–210 BC, was somewhat untypical, and two thousand years ago reliefs were more common, in tombs and elsewhere. Later Buddhist figures were often made in painted and glazed terracotta, with the Yixian glazed pottery luohans, probably of 1150–1250, now in various Western museums, among the most prominent examples. Brick-built tombs from the Han dynasty were often finished on the interior wall with bricks decorated on one face; the techniques included molded reliefs. Later tombs contained many figures of protective spirits and animals and servants for the afterlife, including the famous horses of the Tang dynasty; as an arbitrary matter of terminology these tend not to be referred to as terracottas.
European medieval art made little use of terracotta sculpture, until the late 14th century, when it became used in advanced International Gothic workshops in parts of Germany. The Virgin illustrated at the start of the article from Bohemia is the unique example known from there. A few decades later, there was a revival in the Italian Renaissance, inspired by excavated classical terracottas as well as the German examples, which gradually spread to the rest of Europe. In FlorenceLuca della Robbia (1399/1400–1482) was a sculptor who founded a family dynasty specializing in glazed and painted terracotta, especially large roundels which were used to decorate the exterior of churches and other buildings. These used the same techniques as contemporary maiolica and other tin-glazed pottery. Other sculptors included Pietro Torrigiano (1472–1528), who produced statues, and in England busts of the Tudor royal family. The unglazed busts of the Roman Emperors adorning Hampton Court Palace, by Giovanni da Maiano, 1521, were another example of Italian work in England. They were originally painted but this has now been lost from weathering.
In the 18th-century unglazed terracotta, which had long been used for preliminary clay models or maquettes that were then fired, became fashionable as a material for small sculptures including portrait busts. It was much easier to work than carved materials, and allowed a more spontaneous approach by the artist.Claude Michel (1738–1814), known as Clodion, was an influential pioneer in France.John Michael Rysbrack (1694–1770), a Flemish portrait sculptor working in England, sold his terracotta modelli for larger works in stone, and produced busts only in terracotta. In the next century the French sculptor Albert-Ernest Carrier-Belleuse made many terracotta pieces, but possibly the most famous is The Abduction of Hippodameia depicting the Greek mythological scene of a centaur kidnapping Hippodameia on her wedding day.
Terracotta tiles have a long history in many parts of the world. Many ancient and traditional roofing styles included more elaborate sculptural elements than the plain roof tiles, such as Chinese Imperial roof decoration and the antefix of western classical architecture. In India West Bengal made a speciality of terracotta temples, with the sculpted decoration from the same material as the main brick construction.
In the 19th century the possibilities of terracotta decoration of buildings were again appreciated by architects, often using thicker pieces of terracotta, and surfaces that are not flat. The American architect Louis Sullivan is well known for his elaborate glazed terracotta ornamentation, designs that would have been impossible to execute in any other medium. Terracotta and tile were used extensively in the town buildings of Victorian Birmingham, England. Terra cotta was marketed as a miracle material, largely impervious to the elements. Terra cotta, however, can indeed be damaged by water penetration or exposure or fail through faulty design or installation. An excessive faith in the durability of the material led to shortcuts in design and execution, which coupled with a belief that the material did not require maintenance tainted the reputation of the material. By about 1930 the widespread use of concrete and Modernist architecture largely ended the use of terracotta in architecture.It has been defined as 'Unglazed fired clay building blocks and moulded ornamental building components.'
Terracotta tiles have also been used extensively for floors since ancient times. The quality of terracotta floor tiles depends on the suitability of the clay, the manufacturing methods (kiln-fired being more durable than sun baked), and whether the terracotta tiles are sealed or not.
Advantages in sculpture
As compared to bronze sculpture, terracotta uses a far simpler and quicker process for creating the finished work with much lower material costs. The easier task of modelling, typically with a limited range of knives and wooden shaping tools, but mainly using the fingers, allows the artist to take a more free and flexible approach. Small details that might be impractical to carve in stone, of hair or costume for example, can easily be accomplished in terracotta, and drapery can sometimes be made up of thin sheets of clay that make it much easier to achieve a realistic effect.
Reusable mold-making techniques may be used for production of many identical pieces. Compared to marble sculpture and other stonework the finished product is far lighter and may be further painted and glazed to produce objects with color or durable simulations of metal patina. Robust durable works for outdoor use require greater thickness and so will be heavier, with more care needed in the drying of the unfinished piece to prevent cracking as the material shrinks. Structural considerations are similar to those required for stone sculpture; there is a limit on the stress that can be imposed on terracotta, and terracotta statues of unsupported standing figures are limited to well under life-size unless extra structural support is added. This is also because large figures are extremely difficult to fire, and surviving examples often show sagging or cracks. The Yixian figures were fired in several pieces, and have iron rods inside to hold the structure together.
Terracotta has been the medium for art since the Harappan civilization. But the techniques used differed in each time period. In the Mauryan times, they were mainly figures of mother goddesses, indicating a fertility cult. Moulds were used for the face, whereas the body was hand-modelled. In the Shungan times, a single mould was used to make the entire figure and depending upon the baking time, the colour differed from red to light orange. The Satavahanas used two different moulds- one for the front and the other for the back and kept a piece of clay in each mould and joined them together, making some artefacts hollow from within. Some Satavahana terracotta artefacts also seem to have a thin strip of clay joining the two moulds. This technique may have been imported from the Romans and is seen nowhere else in the country.
The practice of terracotta art and its production continues even today in several states of India. The major centres that continue the practice in modern times include West Bengal, Bihar, Jharkhand, Rajasthan, and Tamil Nadu. In Bishnupur, West Bengal, the terracotta pattern–panels on the temples are known for their intricate details. The Bankura Horse is also very famous and belongs to the Bengal school of terracotta. Madhya Pradesh is one of the most prominent production centres of terracotta art today. The tribes of the Bastar area carry forward the rich tradition. They make intricate designs and statues of animals and birds. Hand-painted clay and terracotta products are famous in Gujarat. The Aiyanar cult in Tamil Nadu is associated with life-size terracotta statues.
Traditional terracotta sculptures, mainly religious, also continue to be made. The demand for this craft is seasonal, reaching its peak during the harvest festival, when new pottery and votive idols are required. During the rest of the year, crafters rely on agriculture or some other means of income. The designs are often redundant as crafters apply similar reliefs and techniques for different subjects. The client suggest subjects and uses for each piece. This craft requires a strong understanding of composition and subject matter as well as skill to effectively to give each plaque its distinct character with patience.
To sustain the legacy, the Indian Government has established the Sanskriti Museum of Indian Terracotta in New Delhi. The initiative encourages ongoing work in this medium through displays terracotta from different sub-continent regions and periods. From the Indus civilization to modern times, the Indian Terracotta school has incorporated various styles, techniques, methods, doctrines, and grammar. It borrows from diverse schools and traditions that range from realism to abstract. In 2010, the India Post Service issued a stamp commemorating the rich craft and its part in India's artistic tradition since the hoary past. The stamp shows a terracotta doll from the craft museum.