Primitive man first became familiar with the concept of "impression" when he realised that he could leave his prints in the sand and the clay. He began using these imprints to express his presence and to enforce his prominence on the nature surrounding him. Pottery was the obvious utilitarian outcome of hand moulding of clay.

The "Culture of impression" lasted until the Era of writing; numerous discoveries, in fact, demonstrated that handprints had a ritualistic or magical significance.

The Sumerians - and consequently all the civilisations of Mesopotamia - made wide use of form by moulding.  Theirs was a brick-built culture.  They also used impressions on clay panels: cylinders in diorite or stone were rolled on the clay leaving cuneiform symbols or ornamental motives impressed.

The Egyptians, however, were the first people to make wide use of gypsum. Gypsum is found in nature in the form of soft stone which can be easily reduced to dehydrated powder by crushing and drying; thanks to its special characteristic of being able to re-hydrate when mixed with water, it becomes malleable before hardening naturally by crystallisation.

Because its texture is superior to clay, plaster was preferred to produce hand- made objects; due to its fire retardant and antiseptic properties, it was used to cover the internal walls of tombs making them sterile. Plaster was also used to impregnate the linen bandages in which the bodies of important deceased people were wrapped, some of which have been mummified until our times.

Also from this period we have the first bivalve moulds in plaster, which were used to model small figures of divinities.

During the Bronze Age (1700 b.C.-750 b.C.) the first forms for holding metal were introduced. Examples of bivalve moulds in stone, belonging to the Camuna civilisation, are conserved in the museum of Capodimonte. These moulds were patiently hollowed out in both halves in order to obtain hand-made articles and tools such as axes, daggers and arrowheads. Once the two halves of the mould were closed, molten metal was poured into the centre. Initially the high temperature of the liquefied metal caused a sudden contraction that made the mould explode so grooves were made to allow the excess metal to drain out. Later it became the practice, which is still used today, to bury the mould in order to make the procedure safer.

It was without doubt the Greeks who reached the highest levels of refinement and perfection in the technique of plaster casts and they also invented the procedure for obtaining moulds of the human body. Their great understanding of their art was due to the fact that the technique of sculpture was not the final aim but it was supported by philosophical principles that celebrated the aesthetic ideal of "mimesis" (that is the perfect imitation of nature) as being the most elevated and desired aim of the artist.

The closer the work was to reality, the greater the sculptor. If the finished statue responded to the aesthetic rules of perfect proportions and if it was realised in such a way as to reproduce difficult and articulate positions, the artist was even considered to be a semi-god who had been guided by divine inspiration.

Documents proving this have been found in various treatises on figurative art; Senocrate of Sicione, for example, considered the sculptor Lisippo (370 B.C.) to be the best because he was even able to reproduce muscle tension with nerves and veins.

The credit for having perfected the proportional relationships between the various parts of the body however goes to Policleto whose "Kanon" earned lasting, universal fame.

Artists in this period were greatly influenced by Plato's theory according to which a total beauty didn't exist in nature. Because of this, the sculptor tended to "construct" ideal beauty with the technique of mould from a living person". Magnificent examples of this are the Bronzes of Riace or the Zeus of Capo Artemisio.

After having obtained various moulds taken from human models which were proportioned and compatible, they were assembled in such a way as to create a statue whose position satisfied all the principles of equilibrium and proportion so that the whole was balanced and free- standing even without the muscular tension of the human body.

Sculptors often adopted different expediencies such as wet drapes or elements attributed to the divinity so as to cover or hide the modelled joints.

The methodology was always that of the "lost form" as it allowed them to have a single copy in marble or bronze from the original in plaster. If a metal was used, they followed the difficult procedure, still used today, and called INVESTMENT CASTING.

After the classical period, the cultural and artistic influence of the tragedy reflected on the educated classes and on the interpretation of the sculpture. No longer did it lean towards an abstract beauty, geometrically constructed, but it became important to search for and express the external manifestations of "pathos".

In the Hellenistic period the ideal reference was to the character and the story of Niobe. The legend tells how the woman dared to compare the beauty of her fourteen sons and daughters to that of the gods, Apollo and Artemis and because of this affront she was punished with the death of all her children. Her sorrow was so great that she turned into stone.

This period gave rise to many statuary groups like those regarding Niobe, which represented the fourteen youths as they were being killed.

Technically the plastic modelling used as a finish for plaster moulds became more important and eventually took over when works of gigantic proportions and bodies with twisting movements were produced. Splendid examples of this are the VENUS by MILO and the NIKE of SAMOTRACE.

The new dynamics typical of open statuary, that is with limbs moving in all directions and with the busts and heads turned, led to a preference for the use of marble, thus limiting the production of works in bronze which had to be produced in a single fusion because the Greeks didn't have knowledge of welding in bronze.

Numerous works were destroyed, plundered or fused and only later were they used for decorating civil architecture where they were nevertheless relegated to the roles of secondary art.

The contempt shown by the Romans towards the Greek artists was probably initiated by their inability to reproduce the realism and refined techniques of the sculpture. Consequently the works of copiers flourished. These copiers were usually Greeks who were given the task of reproducing the works that were considered most significant although by doing so they were reduced to mere duplicates.

The credit goes to Emperor Adriano for having given incentive to this production and for having transported many sculptures from the Hellenic period to adorn his villa in Rivoli. These statues currently constitute the patrimony of many museums including the Capitolini museums. Thanks to Adriano's collections, we can still admire the Venus Capitolina, a copy of the Venus of Cnido by Prassitele and "Eros drawing his bow" produced by Lisippo or again the "Wounded Amazon" which Sosicles had copied from Kresilas.

Although the copiers tried to remain as faithful as possible to the originals, their works were often unable to reproduce the balance of the positions. For this reason they resorted to extra supports such as drapery touching the ground or tree trunks that were against the legs. The difficulties increased when they copied works in marble and bronze or other hard, rigid materials since they couldn't apply the moulding from life, a technique used for the original. In particular they were unable to cover the statue with large plaster forms because the material, filtering into the undercuts such as the pleats in the drapery, expanded and hardened as it dried, thus causing cracks in the marble:

So they refined the technique of "block moulding", the most difficult to use with plaster.

In this way they could reproduce complex groups of statuary such as Lacoonte.

Subsequently, during the fall of the Roman Empire, it became less necessary to copy from real life and more importance was given to creating from imagination. Forms were used less for sculpture and more for decoration and the copiers were replaced by stonecutters, that is artists who cut the stone without prior preparations, thus producing pieces that were unique and individual.

During Medieval times, moulding was looked down upon because the materials used such as clay and plaster were considered poor and without value.

The favourite techniques in this period were painting (frescoes), mosaics and above all, glass as they emphasized the predominance of light and colour on the form. Moulding was nevertheless indispensable as a necessary passage in the process of melting and in the technique used for producing the bronze portals in the cathedrals.

During the Renaissance however, there was a new flourishing period for sculpture which became re- valued together with the entire classical patrimony; art was appreciated both for the technical and theoretical result. The renewed interest for classical antiquity encouraged the collection of works from that period and moulding served to transform many classical statues into bronze. It was at this point in time that the roles of those who worked in this field were first defined. First of all there was the MOULDER, the person in the group who specialized in architectural decoration and who made the MOULDS and the plaster forms so as to obtain casts of linear and repetitive motives with classical decorations. The material in which these were usually made was either stucco or clay.

Once the moulder had produced the copies, the PLASTICATOR took over. It was his job to model the pieces by hand and, if necessary, to finish them with additional material. Finally there was the SCULPTOR who modelled and personally finished the work by controlling the melting or by instructing the pupils how to transform the work into marble. Michelangelo was an extremely gifted sculptor and he was the only artist of that time who, like the stonecutters, was able to produce works by carving directly onto the marble thus gaining the admiration of his contemporaries.

During the Renaissance the use of plaster casts developed in three different spheres; architectural, founding in bronze which often used moulding from "life" and for studying the parts of the human body.

A.Verrocchio (1435-1488) was one of the most expert Florentine sculptors in the use of moulding in plaster. He re- introduced the use of mortuary casting, which had been so popular with the ancient Romans, and also with moulding from "life" finalising it with the study of anatomy as in this way it was much easier to imitate and reproduce the parts of the human body. A good example of this can be seen in Verrocchio's "David" where the head of the giant Goliath seems to be taken from real life as do the remains of "Medusa" (with arms and legs dismantled) at the feet of the victor in Cellini's "Perseus".

Verrocchio's most illustrious student was LEONARDO who, however, didn't share the practice of copying from "life" to which he had been subjected as an apprentice and he grew up with a poor consideration for sculpture considering that volume could only be obtained through design. He claimed that marble tended to flatten the figures while he preferred the use of bronze where the luminous effect rendered the work more perspective.

Although this brilliant artist carried out his studies of the human body on paper, his contemporaries produced real anatomical sculptures that began with analysing the skeleton and the subcutaneous musculature. Among these works are those by Michelangelo and those by Bartholomew Bandinelli.

Among the most famous sculptures, the figure of Saint Bartholomew deserves a special mention. It can be seen in the transept of the Duomo of Milan and it represents the saint standing completely stripped of his skin, which is thrown over his shoulder, as if it were a cape. In fact, apart from its interpretation of the martyr, it was used by many artists to study anatomy.

With the urban renewal of Rome at the beginning of the 6th century, moulding was widely used for restoration. Interest in archaeology increased and many of the marble works that were discovered were restored and the missing pieces were replaced.

In Italy the first collection of plaster casts was due to the sculptor LEONE LEONI (1509-1590) from Menaggio who obtained the authorisation from the Pope to carry out a cast of the horse of Marco Aurelio which, in that period, had been placed in the centre of the square in Campidoglio on Michelangelo's wishes.

Shortly after, on the request of Maria of Austria, Queen of Hungary, Leone Leoni produced plaster copies of the statue to be then cast in bronze.

They were then transported by mule to Milan where they were put on display in the quadriportico of the sculptor's palace, giving origin to the modem idea of plaster cast galleries. (gipsoteca)

The pleasure and wonder that people could get from admiring these marvellous works without travelling to Rome was enormous and it became popular for Princes and Rulers to obtain prestigious copies with which to embellish their own homes.

On his death, Leoni's collection was left to the CALCHI family and so locally reproductions in plaster were called "dei Calchi" (of Calchi) and then, consequently, "the calchi" (the casts).

Once the phase of collections was over, workshops and private schools were transformed on an institutional level into Academies, which then proposed to abandon mannerism in favour of a renewed interest in reality.

Moulding was considered a useful means of artistic education and so it was taught in the schools.

At a later date, Neo- classicism started the cult of classical works, which were considered prototypes of formal beauty, but without ever reaching a spiritual adhesion to the antique ideals.

Many people followed the philosophical theories of Winckelmann who, in order to simplify the relationship between beauty and spirituality in art, elevated Classicism to a position of superiority for balance, harmony and perfection.

Collections of plaster copies in the Academies increased and this gave rise to a number of plaster cast galleries where the students could go periodically to gain practise in the "poor" art of copying works of art.

In 1776, Maria Teresa of Austria promoted the foundation of a new academy in Milan at the palace of Brera, but it was not possible to transfer the plaster casts from the Biblioteca Ambrosiana, as had been requested by the Austrian governor, as the founder, Cardinal Federico Borromeo, had donated them only on the condition that they were not to be moved.

It was only during the Napoleonic period that the Gipsoteca of Brera became more vital thanks to the rector Giuseppe Bossi who requested, and obtained directly from Napoleon, plaster casts from the Louvre. Others arrived from Rome and Mantua. Antonio Canova, the inspector of antiques of the Belle Arti, managed to obtain the moulds of the marble of Fidia of the Parthenon and that of the bas-  relief of the Madonna and child.

Canova was an brilliant sculptor who interpreted the classical canons in a unique and personal way. He preferred to use white Carrara marble for his works because of the superficial transparency it gained when polished. He was also a keen collector of antique sculptures.

Even in his works in plaster, still today on display in the Plaster Gallery of Possagno, Canova rendered their surface as glossy as that of marble by means of a special finish.

In the second part of the 19th century, the neo-classical style gave way to the romantic style and this was the start of a slow decline of sculpture inspired by antiquities as they were considered a pagan element.

The formation of aspiring artists was mostly directed towards painting and studies from real life.

Moulding became popular again during the Liberty period where it was widely used for architectural decorations inspired by ornamental and figurative designs.

During the 1930s, because of the growing popularity of rational architecture, decorative motives were almost totally abolished and the use of plaster moulds was reduced, even in the restoration of buildings where it had always had a wide application. In this field, the technique of "re-building" gave way to "preservation" and decorations with missing parts were no longer completed but left as they were.

Despite everything, plaster casts have the prestigious role of conserving antiquity. Many original statues and bas-reliefs which were destroyed or lost, even during the Second World War, or which have deteriorated over the years, can now be seen and appreciated only through their copies. Today the reproduction of antique sculptures is once again becoming important as it has become necessary to remove the originals from the damaging effects of atmospheric pollution and to save our artistic patrimony for future generations.

At a more mundane level, moulding plastic is central to industries producing everything from car bodies and furniture to toy soldiers. An under-appreciated, but critical, sector of Japanese manufacturing is the country's mould-makers. Tiny, secretive firms generally consisting of less than a handful of workers, these craftsmen usually work in what look like dim, grimy, oversize garages, filled with worn machines and piles of scrap metal. Industrial moulds are used to create the shape and form of almost anything that can be picked up, from ballpoint pens and toys, to mobile- phone and satellite parts. The work is highly specialised. Many mould-makers, now in their 50s and 60s, started learning their trade when they were children.

The best firms, clustered around Ota, Shinagawa and Sumida wards in south and east Tokyo, make moulds, often prototypes, for the top international names in cars and consumer- electronics—and even for NASA, America's space agency. Mould- making technology lies at the base of all manufacturing.