Apart from their aesthetic and historic value, archaeological objects provide a lot of information about ancient craftsmanship. In this section you can learn about the materials and tools used by the ancient craftsmen and the main manufacturing techniques for various types of artifacts.
Nikolas Papadimitriou, Curator MCA
Clay was the basic material for the production of any type of container in antiquity. Clay is a deposit of the smallest particles produced by the weathering of certain rocks. It is composed mainly of aluminium, silicates and water. It is widely available in surface and underground layers, largely varying from each other in composition and colour according to the conditions of deposition. When fired, clay becomes extremely hard and water-proof (baked clay is also known as "terracotta").
Pots of baked clay have been used ever since humans abandoned the nomadic way of life and established permanent settlements. In Mesopotamia, this transition dates from the 9th millennium BC, while the earliest permanent settlements in the Aegean date from the end of the 8th millennium BC. Initially, clay vases were handmade. About 3400 BC, however, the potter’s wheel was invented in Mesopotamia, making it possible to produce more symmetrical vases of practically any shape. The potter’s wheel was introduced in the Aegean at the end of the 3rd millennium BC.
Clay vases were used in all spheres of life, from household activities and trade to religious ceremonies and burial. Cooking and storage vessels were usually made of coarse fabric and left plain. Those that were destined for banquets, rituals, funerary ceremonies or commercial exchanges were finely made and lavishly decorated. Their production was a complex process involving several stages.
Pottery manufacture and decoration may vary considerably among different regions and periods. Ancient Greek potting and vase-painting techniques are known, among others, though a number of representations preserved on clay plaques and vases of the Archaic and Classical period. Here we use simplified versions of such depictions to follow the main stages of the manufacturing process:
• First, clay was extracted from deep natural pits. It was then sieved and washed to remove impurities. Next, small particles of other materials (e.g. sand, straw, shell) were added to make the clay harder and more resistant to cracking.
• The potter placed a lump of wet clay on the wheel, a large circular slab made of stone or wood. The centrifugal force caused by the rotation of the wheel enabled him to give the vase the desired form. Handles and plastic elements were added after the pot was ready.
• After the pot had dried, the vase-painter covered the surface with decorative motifs. Decoration was rendered in outline, silhouette or more elaborate techniques.
• When the decoration was completed, the vases were placed in kilns, where they were fired for 6-8 hours in temperatures exceeding 900oC. By controlling the flow of oxygen in the kiln, the potter successively created an oxidizing and a reducing atmosphere, which helped pigments to solidify and adhere permanently to the clay.
Black figure and red figure vases
As a rule, ancient Greek vases were decorated before firing. Figures and other decorative motives were drawn and painted while the clay was still wet. When fired, the “colours” permeated the porous body of the clay and became firmly attached to the vase - which accounts for the excellent preservation of the decoration in most ancient Greek pots.
The Greek potters, however, did not use pigments for the decoration of vases. Instead, they exploited the chemical reaction of iron oxides present in clay, during the firing process. These turn red when fired in an oxidizing atmosphere and black if fired in a reducing atmosphere (without the presence of oxygen).
The properties of iron oxides were known already in later prehistory but their full potential became realized and exploited only in the Archaic and Classical periods. The famous black-figure and red-figure vases with their perfectly preserved glossy surfaces are masterpieces of potting, decorative and firing skills.
So sophisticated is the technique involved in their production that archaeologists were unable to understand and re-create it successfully until the 1940's. Today we have a sound chemical and archaeological documentation of the process. Here are the basic stages:
A. Drawing the figures and decorative motifs
Vase-painters started working only after the clay had dried sufficiently. First, they sketched the figures and other decorative motifs in outline and then, they applied clay slip (fine clay diluted in water) on the surface. To achieve the differentiation into black and red, different parts of the vase were covered with different kinds of clay slip:
- a fine slip, poor in ferrous particles, for the areas that were to be red
- a thick layer of clay slip, rich in ferrous particles, for the areas that were to be black.
B. The firing process
After decoration was completed, the vase was set in the kiln, where it was fired for 6-8 hours. The firing process was identical in both the black-figure and the red-figure technique. It involved three phases, with an oxidizing, reducing, and re-oxidizing atmosphere. This alternation in the flow of oxygen affected in different ways the two types of clay slip and resulted in the creation of glossy red and black surfaces.
These are the basic principles for decorating and firing simple black- or red-figure vases. In practice, of course, the process was much more complex. Exceptional skills were needed to draw the details of the figures, prepare the "colour" slips and apply them with precision on the surface of the vase. Temperature control was, also, important and required continuous testing of the firing conditions and great experience in managing the supply of fuel.
Artistic considerations could also increase complexity. Sometimes, Greek potters - especially those working in the black-figure technique - chose to highlight certain parts of their compositions with other colours; for example, white or ochre was frequently used for women's flesh, violet for hair, bears and garments, etc. These "added colours" were in fact fine clay slips of different composition that were applied over the thick ferrous slip of the figures before firing. More often than not they survive well, although sometimes they flake-off - and indication of improper firing.
Mining and preparation
Bronze was of vital importance in antiquity. It was one of the basic materials for the manufacture of tools and weapons, and it was also used for ornaments, figurines, and even statues. It is because of its importance that a whole era has been named after it (the "Bronze Age"). Bronze, however, is not a naturally occurring metal but a copper alloy, usually with tin as the main additive.
Copper is usually found mixed with other metallic elements in ores (e.g. azurite, cuprite). The ores have to be smelted at high temperatures (approximately 1.100οC) to separate the copper from the other elements.
In antiquity, smelting was carried out in large clay furnaces filled with successive layers of ore and charcoal. Blow-pipes or bellows were used to introduce air into the furnace in order to raise the temperature to the desired level. The molten copper flowed into stone or metal bowls through a hole at the bottom of the furnace. It was then re-melted and cast in ingots of standard weight.
Pure copper is extremely malleable and was used only on a limited scale for small items and ornaments. Much more durable copper alloys were required for the manufacture of weapons, tools, vases and statues. In ancient times, copper was alloyed either with arsenic (arsenical copper) or, more commonly, with tin (bronze).
Two main methods were used in antiquity for the manufacture of copper and bronze objects:
A) the working of thin metal sheets with hammers and punches
B) casting in various types of moulds.
Fire was essential in both techniques, either to melt the metal for casting or to heat the copper/bronze sheet (“annealing”) so that it would remain malleable and easy to work.
Weapons and tools - Mould casting
During the 3rd and 2nd millennium BC, bronze was the favourable material for the manufacture of weapons and tools. Various types of copper alloys were used to make swords, daggers, knives, arrowheads, spearheads, as well as a vast range of tools. Even after the introduction of the more durable iron, early in the 1st millennium BC, certain types continued to be made in bronze. Tools and weapons were invariably cast in moulds.
Vessels - Casting and sheet-working
Metal vessels were made in the Aegean over a long period of time (from as early as the 3rd millennium BC) and in a wide range of shapes. They were costly and had both practical function (e.g. as containers in rich houses and luxurious symposia) and symbolic use (e.g. as precious offerings in shrines or burial gifts). Gold and silver vessels are only rarely preserved, no doubt because they were melted down and re-used in antiquity. Bronze vessels are much more numerous and allow us to study in detail their technology. Although they are often described as "hammered from a sheet of bronze", in fact their manufacture involved a combination of casting and sheet-working techniques.
Figurines - Solid "lost-wax" casting
The art of casting solid bronze figurines of humans and animals was known in the Near East and Anatolia already from the 3rd millennium BC. In the Aegean, the earliest examples come from Minoan Crete and date to the 16th-15th c. BC. They became particualrly common in the Geometric period, when they were placed as votive offerings in sanctuaries, and continued to be produced in considerable numbers until late antiquity. Bronze figurines were invariably cast in the "lost-wax" technique (known also by the French term "cire-perdue").
Statues - Hollow "lost-wax" casting
Large bronze statues were almost invariably cast and hollow inside (otherwise the amount of bronze required would be tremendous, as would be also the cost and the weight of the statue!). The sculptor did not work directly on the bronze, but first prepared a model in clay (or wood) and wax. This was handed over to the foundry, which produced the bronze statue by the technique known as "hollow lost-wax casting".
This technique (known among specialists as the "direct method") was destructive for the original model. Around the middle of the 5th c. BC, the Greeks developed an even more sophisticated casting process (termed "indirect method") which allowed for the preservation - and re-use - of the model. We should, finally, stress that large-size statues were normally made of several parts (head, torso, arms, etc.) which were cast individually and then welded or riveted to each other.
Since prehistoric times, gold has been highly appreciated for its remarkable qualities. In addition to being shiny and rare, it is soft and ductile – which makes it easy to work – and practically indestructible.
Gold occurs naturally in metallic form, either in vein deposits or in river-beds (as dust or nuggets). It can be easily extracted either by grinding the rock or by sieving the river sand; water is then used to flush away the waste material (in ancient times, sheep fleeces were used to retain the small particles of gold during washing – hence the legend of the Golden Fleece). Native gold contains small amounts of other metals (mainly silver and copper) and needs to be refined through smelting if pure gold is required. Although gold refining is attested already in the Late Bronze Age, it was not generally practised until Classical times.
The earliest known gold jewellery in the Aegean dates from the 5th-4th millennium BC. Greece had limited sources of gold, in Macedonia, Thrace and the islands of Thasos and Siphnos. Therefore, gold was also imported from the Black Sea, the Balkans, Egypt and the Near East.
Today, most gold jewellery is cast. In antiquity, however, goldsmiths worked mainly on sheet metal. A small quantity of gold was first cast in the form of a convenient small mass, which was then hammered into a thin sheet - usually less than 1 mm thick.
Simple tools made of wood, bone or metal were used to produce intricate ornaments in various shapes, often composed of several pieces; the pieces were joined together with the use of some kind of bonding agent and intense heating. Sometimes, various techniques were combined in a single ornament.
The impressed technique was one of several methods used in antiquity for working sheet metal. Since it was based on the use of a die, it allowed for the production of multiple copies. Carving the motif on the die was probably the most difficult part of the process.
Granulation is the technique of producing minute spherical drops ("grains") of gold and soldering them against a background. It is a very demanding process that required exceptional skills not only in making the tiny grains (which sometimes were less than 0,2 mm. in diameter) but also in handling and soldering them together. Nevertheless, it was extensively used from the Middle Bronze Age onwards for the decoration of ornaments and also vessels.
Gold wire was used for a variety of purposes. Together with the metal-sheet, they were the most essential elements of ancient jewellery. Goldsmiths used wires both for functional parts of an ornament (e.g. suspension loops for earrings, rings, pins, etc.) and for decorative motifs. Gold wires were thin, solid, and usually circular in section. They were mostly made of metal sheet.
Repoussé and chasing is the term used to describe the most sophisticated technique of metal sheet working in antiquity. By contrast to other methods which made use of dies, in repoussé the craftsman worked directly on either side of the metal sheet using a variety of hammers and punches. It was an extremely demanding technique in skill and time, but the results were both original and unique. In the Aegean, the first artifacts made by repouseé and chasing date back to the 2nd millennium BC. However, the technique is much older and must have originated in the Near (or Middle) East.
Small items were frequently decorated simply by pressing the gold sheet onto a wooden, metal or clay core (“former”).
Sometimes, the decoration of very thin gold-sheet ornaments was rendered in the cut-out technique.
The origins of glass technology
We have little information about the origins of glass technology. In all probability, glass was invented in Mesopotamia during the 4th or 3rd millennium BC, although Egypt has also yielded some very early examples. The first glass vessels appeared in both areas in the 16th c. BC and were core-formed. Glass technology evolved at a rather slow pace (the exclusive character of the profession may have been one of the reasons) until the Roman Period, when the invention of the glass-blowing technique brought about a real revolution both in the production and circulation of glass (see below).
In Greece, glass objects are known already from Mycenaean times, although no workshops of that period have been discovered so far. In the early first millennium it was the Assyrians and Phoenicians who were most active in the manufacture and trade of glass artifacts. A large amount of elegant glass objects is known from the Aegean of the same period. We do know that an important workshop existed in the island of Rhodos, but otherwise our knowledge of the organization of production is very limited.
The main techniques
Core-forming was the most widely-used technique before the invention of glass-blowing. In the Aegean, it became particularly popular from the later stages of the Archaic period onwards. In brief, the process can be described as follows: at the tip of a wooden or metal rod the craftsman attached a core made of fire-proof material (e.g. clay) and then coated it with molten glass until it was completely covered. Frequently, for decorative purposes, the craftsman used thin glass bands of various colours in molten form, which he pulled across the surface in wavy, zig-zag or linear patterns. When the decoration was complete, he added such features as the neck and the handles, which were made separately.
Glass vases made in that technique are small in size, imitating ceramic types (amphoriskoi, aryballoi, oinochoai etc.). They were placed in graves, as offerings to the dead, or used in daily life, most probably as luxurious containers for perfumes.
Apart from core-forming, there were other techniques used in that period: mosaic glass, casting in an open mould, and cutting. In the Hellenistic period elegant new techniques were invented, such as the use of thin gold sheets between layers of transparent glass, and cameo (relief decoration in light-coloured glass upon a dark glass background).
The single most important event in the history of glass technology was the invention of glass-blowing, which took place in Syria sometime in the 1st c. BC. In principle, the technique has remained unaltered until today. The craftsman blew through a blowpipe into a glob of molten glass, which inflated slowly; then he shaped the object either by rolling the inflated glass on a flat surface or by using a mould.
The process was simple and allowed for the production of practically any shape, thus freeing glassmakers from the restrictions imposed by earlier techniques. Simplicity in manufacture led eventually to mass production and the subsequent decrease in the price of glass objects. Glass became very popular in every-day life; glass vessels not only were more practical and elegant than pottery but also preserved liquids more effectively.
Glass-making and glass-working
The production of glass artifacts is a complex process that involves two distinct stages. The first one has to do with the production of artificial glass. The second one has to do with the fashioning of the material, in order to create various types of objects.
Although glass appears in natural form (e.g. obsidian), the material used to produce glass vases, mirrors, and other objects is artificial. Three basic components are needed for its manufacture: sand, some kind of alkali (e.g. soda), and lime; the components have to be fused together in very high temperatures, (exceeding 1300ο C). Once this is done, a variety of techniques can be used in order to work the glass.
Information about the techniques used in the glass industry derives from ancient sources and the study of glass objects themselves, as well as from experimental efforts to produce glass artifacts using ancient methods. Research has made considerable advances in that area, yet there are significant gaps in our knowledge.
In antiquity, glass was thought to carry magical qualities and its manufacturing technique was covered in a cloud of mystery. Until Roman times, glass was a rare and luxurious material, almost as precious as gold. In ancient Greek literature, there are three terms relating to glass. The word “kyanos”, used in Mycenaean Linear B tablets, refers to a dark blue, shiny material. In later Greek texts, we find the terms “lithos chyte” (molten stone) and “hyalos”; the latter term, of unknown origin, is used even today in Greek for glass.
The core-forming technique is so-called because the vase was made by trailing molten glass around a core of clay or other material, which had been roughly shaped in the desired form. It is the most ancient technique of making glass vessels. The earliest known examples date to the 16th-15th c. BC.
In the free-blowing technique, the craftsman shapes the vase by blowing air with a metal pipe into the molten glass. The method was invented in the mid-1st c. BC, most probably in some Syrian or other Levantine workshop. Since then, free-blowing has been a particularly popular method of producing glass vessels.
• Αλούπη Ε. 1993: Φύση και μικρομορφολογία των βαφών σε αρχαία κεραμικά. Μια νέα προσέγγιση στη μελέτη της κεραμικής τεχνολογίας (PhD, Πανεπιστήμιο Ιωαννίνων)
• Βοκοτοπούλου Ι. 1996: Ελληνική τέχνη. Αργυρά και χάλκινα έργα τέχνης στην αρχαιότητα (Αθήνα)
• Δεσποίνη Αικ. 1996: Ελληνική τέχνη. Αρχαία χρυσά κοσμήματα (Αθήνα)
• Κόντου Ελ. – Κοτζαμάνη Δ. – Λαμπροπούλου Β. 1995: Γυαλί: Τεχνολογία, Διάβρωση και Συντήρηση (Αθήνα)
• Τριανταφυλλίδης Π. 2000: Ροδιακή Υαλουργία Ι (Αθήνα)
• Bol P.C. 1985: Antike Bronzetechnik. Kunst und Handwerk antiker Erzbildner (Munich)
• Branigan K. 1974: Aegean Metalwork of the Early and Middle Bronze Age (Oxford)
• Carroll D.L. 1972: "Wire drawing in antiquity", American Journal of Archaeology 76, 321-323
• Carroll D.L. 1974: "A classification for granulation in ancient metalwork", American Journal of Archaeology 78, 33-39
• Carroll D.L. 1983: "On granulation in ancient metalwork", American Journal of Archaeology 87, 551-554
• Coghlan H.H. 1956: Notes on the Prehistoric Metallurgy of Copper and Bronze in the Old World (Oxford)
• Cuomo di Caprio N. 1985: La Ceramica in Archeologia. Antiche techniche di lavorazione e moderni metodi d' indagine (Roma)
• Davidson P.F. - Oliver A. 1984: Ancient Greek and Roman Jewellery (New York)
• Deppert-Lippitz B. 1985: Griechischer Goldschmuck (Mainz)
• Deshayes J. 1960: Les outils de bronze de l" Indus au Danube (IVe ou IIe millenaire) (Paris)
• Diehl E. 1964: Die Hydria: Formgeschichte und Verwendung im Kult des Altertums (Mainz)
• Evely R.D.G. 2000: Minoan Crafts. Tools and Techniques: an Introduction (Jonsered)
• Finn D. - Houser C. 1983: Greek Monumental Bronze Sculpture (New York)
• Forbes R.J. 1966: Studies in Ancient Technology V (Leiden)
• Forbes R.J. 1971: Studies in Ancient Technology VΙΙΙ (Leiden)
• Forbes R.J. 1972: Studies in Ancient Technology IX (Leiden)
• Goldstein S.M. 1979: Pre-Roman and Early Roman Glass in the Corning Museum of Glass (New York)
• Grose D.F. 1989: Early Ancient Glass: Core-Formed, Rod-Formed, and Cast Vessels and Objects from the Late Bronze Age to the Early Roman Empire, 1600 BC to AD 50 (New York)
• Harden D.B. 1968: "Ancient glass, I: pre-Roman", Archaeological Journal 125, 46-72.
• Harden D.B. 1969: "Ancient Glass, II: Roman", Archaeological Journal 126, 44-77
• Haynes D. 1992: The Technique of Greek Bronze Statuary (Mainz)
• Healy J.F. 1978: Mining and Metallurgy in the Greek and Roman World (London)
• Higgins R.A. 1980: Greek and Roman Jewellery2 (London)
• Hodges H. 1989: Artifacts. An Introduction to Early Materials and Technology (London)
• Hoffman U. 1962: "Die chemischen Grundlagen der griechischen Vasenmalerei", Angerwandte Chemie 74, 397-406
• Lamb W. 1969: Ancient Greek and Roman Bronzes (Chicago)
• Lapatin K. (ed.) 2008: Papers on Special Techniques in Athenian Vases. J. Paul Getty Museum Publications (Los Angeles)
• Matthäus H. 1980: Die Bronzegefässe der kretisch-mykenischen Kultur (Munich)
• Mattusch C.C. 1996: Classical Bronzes: The Art and Craft of Greek and Roman Statuary (Cornell)
• Mitten D.G. - Döringer S.F. 1968: Master Bronzes from the Classical World (Mainz)
• Newby M. – Painter K. (ed.) 1991: Roman Glass. Two Centuries of Art and Invention (London)
• Nicolini G. 1990: Techniques des ors antiques (Paris)
• Noble J. 1988: The Techniques of Painted Attic Pottery2 (London)
• Ogden J. 1982: Jewellery of the Ancient World (London)
• Ogden J. 1992: Interpreting the Past: Ancient Jewellery (London)
• Pfommer M. 1987 : Studien zur alexandrischer und grossgriechischer Toreutik frühhellenistischer Zeit (Berlin)
• Richter G.M.A. 1923: The Craft of the Athenian Pottery (New Haven)
• Richter G.M.A. 1970: The Sculpture and Sculptors of the Greeks4 (New Haven)
• Robertson M. 1992: The Art of Vase-Painting in Classical Athens (Cambridge)
• Rolley C. 1969: Les statuettes de bronze (Paris)
• Rolley C. 1982: Les vases de bronze de l’ archaisme récent en Grande Grèce (Naples)
• Rolley C. 1983: Les bronzes grecs (Paris)
• Rolley C. 1994: La sculpture grecque (Paris)
• Scheibler I. 1983: Griechische Töpferkunst (Munich)
• Schumann T. 1942: "Oberflächenverzierung in der antiken Töpferkunst. Terra sigillata und griechische Schwarzrotmalerei", Berichte der deutschen keramischen Gesellschaft 23, 408-426
• Snodgrass A. 1964: Early Greek Armour and Weapons (Edinburgh)
• Stewart A. 1993: Greek Sculpture: An Exploration (New Haven)
• Thomas R. 1992 : Griechischen Bronzestatuetten (Darmstatt)
• True M. - Podany J. (ed.) 1990: Small Bronze Sculpture from the Ancient World (Los Angeles)
• Tylecote R.F. 1976: A History of Metallurgy (London)
• Untracht O. 1982: Jewellery Concepts and Technology (London)
• Verlinden C. 1984: Les statuettes anthropomorphes crétoise en bronze et en plomb, du IIe millenaire au VIIe siècle av. J.-C. (Louvain-la-Neuve)
• Von Saldern A. 1980: Glass - 500 BC to AD 1900. The Hans Cohn Collection (Mainz)
• Weinberg G.D. 1992. Glass Vessels in Ancient Greece (Athens)
• Williams D. - Ogden J. 1994: Greek Gold. Jewellery of the Classical World (London)
• Winter A. 1959: Die Technik des griechischen Töpfers in ihren Grundlagen (Mainz)
• Zimmer G. 1990: Griechische Bronzegusswerkstätten: Zur Technologieentwicklung eines Antiken Kunsthandwerkes (Mainz)
• Zimmermann J.-L. 1989: Les chevaux de bronze dans l’ art géométrique grec (Mainz)