CERAMIC TECHNIQUES

Ceramic techniques are very varied and have an ancient history. The ways of working traditional pottery allow us to achieve unique results, so each piece has its own history and “destiny”.

In this article we are going to talk about this type of techniques, which once known, are simple to use, although to master them completely there are craftsmen who say it can take a lifetime.

You will see that some of them can be made together and thus achieve endless combinations that allow multiple and beautiful creations in artistic ceramics to materialize.

We are going to talk first about the fundamental part of everything, the material for ceramics, which is the clay and its previous kneading. Then we will explain the necessary techniques in ceramics grouped according to three criteria: techniques applied to the shape, the color and the type of firing.

Now, the first step to all of them will be to tell you about the clay, and to insist that the main thing is a good choice at the beginning of the material with which we are going to work.

WHAT TO DO WITH CLAY

There are endless possibilities, which is why it is so rewarding for the artist to explore new ways of working with clay and to try the same technique with different variations.

Clay is a relatively readily available material, accessible in nature and its many varieties provide an incredible wealth of possibilities.

Clay is one of the most versatile and easy-to-handle materials for learning to sculpt. A large block of clay is easy to mold and is used by beginners and professional sculptors alike to make beautiful works.

In the history of art we can find an infinity of techniques in artistic ceramics and within each one, different ways of developing it, giving continuously original and new results.

These methods and their results depend on the materials and tools available, the cooking method and, of course, the creativity and skill of each person.

We primitive art lovers enjoy seeing what can be achieved with just clay, a stick, a pebble, our hands and a fire.

With these five elements we can develop basic techniques such as hand modeling, the most direct way to produce a piece, and to this piece we can apply different decorative techniques in ceramics.

There are a multitude of ideas about what can be done with clay: pieces of tableware, soap dishes, pots, cups or simply create without any functional use, which is not at odds with handmade ceramics, we can work the sculpture without further ado.

CHOOSING CLAY

There are many types of modeling clay, to choose one that suits what we want to do, we must take into account what is the end result we want, what firing it will need, the experience we have working with it (as some require more expertise than others) and the cost of it.

For example, some materials will require a higher temperature than others: it will not be the same to use a red clay or terracotta, which can be fired at less than 1800º F, than to use a kaolin for a porcelain piece, which will require more than 2200º F.

Some clays are more ductile than others, and behave differently.

We must take into account all the elements for this first step which is to choose the type of clay to use, if we do not have much experience or we are not sure what kind of work we want to do, we can always try several different clays and take them to the limit to see how they behave and with which we feel more comfortable.

CERAMIC TECHNIQUES APPLIED TO THE SHAPE

The first thing we must do with the clay piece is the kneading, essential if we do not want to have “surprises” when we continue working the piece or at the time of firing, such as having air bubbles. In the blog you can read more about how to knead the clay.

TIPS ON CLAY MODELING:

It is necessary to prepare a suitable environment. To model the clay we must use a sufficiently large surface, which must be at a suitable height so that the back does not suffer, and it must also be stable and resistant, bearing in mind that to model the clay it is necessary to use some force, exerting pressure.

We must have all the materials ready, including having water and wetting cloths at hand. It is important to know how long it takes for the clay we are going to use to dry, in case we are working on separate pieces or we are going to model the clay at different times. Sometimes we will not only have to moisten the work but also leave it covered.

Always make sure that no air pockets or air zones are generated in the piece we are creating.

THE MAIN METHODS AND TECHNIQUES YOU NEED TO KNOW:

We are now going to talk about the main techniques used in artistic ceramics, those that work their shape and those that are merely decorative.

Working the shape of the clay:

• Pinch” technique: Forming a ball of clay with your hands, keeping the right humidity and pressing with your thumb to make a hole inside the ball, in this way we can enlarge the void until we give it the shape of a bowl, cup, etc. With this method the hollow is created but without extracting clay and using the fingers, unlike the Japanese Kurinuki method, (which we explain below) by which the clay is removed from the inside using tools.

• Slab technique: This is used to obtain more or less flat shapes to work with. On a cloth or suitable surface, the clay pellet is crushed with a roller until a plate with the extension and height that we need is achieved, then it can be cut to use it as a base, to form cylinders or other shapes.

• Coiled pottery: Pieces of the desired size are separated from the piece of clay to be rolled, flattened and elongated to form rolls that we will use to form the figures we want with them.

Ceramic decorative techniques:

• Incised pottery: Playing with high relief and low relief. It consists of applying incisions or marks on the surface of the wet clay or in a “leather-hard” state.

• Impression: Applying with relative force an object on the surface of the piece, leaving its imprint on it. Elements of nature are frequently used.

• Added: Gluing clay decorations by means of slip on the surface of the piece, as in corded or gallonada ceramics.

• Burnishing: This method consists of polishing the surface of the piece by rubbing it with a smooth element to generate a smooth and shiny surface mechanically, without the need to use enamels.

• Sgraffito: Creating drawings through the contrast of colors or textures.

These ceramic decoration techniques have continued to be used and developed throughout history since it is the simplest and most instinctive way of working with clay. You can also play with the combination of them obtaining very different and beautiful results.

CERAMIC TECHNIQUES APPLIED TO COLOR

If with these techniques we have mentioned above we work the shape, the color would be given by the use of different types of clays, engobes, glazes and by the type of firing.

THE USE OF ENGOBE:

It is a mixture of white or water-colored clay, oxides with which to generate different colors and other elements. With this we obtain a semi-liquid slurry that is applied on the piece still with some moisture but already quite consistent, which is called leather-hard. The colors that we obtain by means of this procedure are matte and soft, to give them more intensity we can burnish the piece, just applied the engobe, with a pebble or some object of smooth surface.

It has been used throughout history in different times and cultures and is applied in many ceramic decorative techniques.

In the 7th century B.C. in Greece an engobe was used to which alkali was added, obtaining a mixture of very fine particles and which was applied before the first firing. In the 1st century B.C., in Rome the so-called terra sigillata was created, in which the pieces were covered with an engobe, initially in black and later colored in red, which gave shine and waterproofing to crockery and skylights.

It is very attractive the way it is used in the pre-Columbian pieces, full of color, and the legacy it has left in today’s Mexican ceramics.

If you are interested, you can learn more in our engobe guide.

The Moca ceramic technique:

It is worth mentioning this method that consists of covering the piece with a layer of light alkaline engobe, then, after preparing an acid and darker mixture, which traditionally contains tobacco and oxides, it is poured over the alkaline engobe that has not yet solidified. The difference in pH and color between the two fluids will cause beautiful branching effects that will give a natural effect decoration with curious mixtures and branches of different tones.

CERAMIC GLAZE:

The glaze is a compound in suspension formed by fluxing materials and quartz that when applied on the surface of a ceramic piece and then fired in a ceramic kiln at the appropriate temperature, results in a semi-vitreous surface that waterproofs the piece and adds another aesthetic quality.

The origins of enamels are in the Middle East.

In Egypt, at the beginning of the Eneolithic period, the first blue and green glazes, so characteristic of Egyptian ceramics, appeared. These glazes were obtained by mixing pulverized rock crystal, lime, potash and copper carbonate, hot amalgamated, crushed in water and spread on the pieces, which were then placed in a kiln.

In the ancient pre-dynastic period, what we now call Egyptian paste was invented, the first step towards the creation of glass, composed of a finely ground mass of silica, sand or quartz, to which the rather thick enamel envelope lends cohesion.

From Assyria we have a baked clay tablet, kept in the British Museum (tablet no. 120960) where the formula of a lead and copper enamel (green), where Liballit-Marduk, from Babylon (C. 1,700 B.C.), tells us the procedure from the extraction of the zuku-glass mine.

From 800 B.C. onwards, the use of the ceramic glazing technique began to transcend in an appreciable way. In the West it was continued by the Romans and in the East it has been known since the Han Dynasty (202 B.C. – 220 A.D.).

CUERDA SECA TECHNIQUE:

Related to the application of colored glazes, this traditional method, which originated in what is now Andalusia, has come down to us today. The cuerda seca technique is a reference of the Spanish pottery tradition. It consists of previously delimiting the different zones where we are going to apply each glaze, making the drawing with incisions and filling them with a greasy material that will act as a “barrier”. It is used mainly in tiles.

MOSAIC

It is also related to the tiles, however, in this case it is not to create them as in the dry rope, but what we do is to take pieces of such tiles, glass, various types of tiles and other materials, which are broken and join them to form figures. The elements that make up the decorative patterns are called tesserae, we speak here of the mosaic technique in ceramics since, in a way, we work with it by recycling fragments of pieces that are already broken and, on the other hand, it could be considered a color technique, since the fragments are forming figures taking into account color patterns that generate contrasts of background and shape to distinguish the different artistic elements.

This method, which is well known, although it has different varieties, basically consists of joining the tesserae on a flat surface using an adhesive. In the past, mortar was more commonly used, today mortar glue or any other synthetic adhesive is used. The most important thing about this material is that it must have a sufficiently long “open” or hardening time for us to be able to work with it. A coat of enamel, for example, can be applied to the final result.

The mosaic technique has been used since ancient Egypt through the Roman Empire (from pavements to murals) and by different cultures up to the present day; for example, Gaudí used this type of work extensively in his work.

CLAY FIRING TECHNIQUES

The way of firing ceramics from the open fire (30,000 years old and probably more) and its evolution to different types of wood-fired kilns and the appearance of new energy sources that gave rise to gas, oil and electric kilns, generates different technical possibilities and consequently different finishes.

The firing of the clay at temperatures above 1100ºF causes the piece to undergo a transformation in its chemical composition, which gives it a hardness similar to stone and it can no longer return to its clayey state if it gets wet.
In open fires, typical of Neolithic pottery production throughout the world, firing temperatures do not exceed 1600ºF.

With the passage of time, the use of heat in ceramic kilns was optimized, building closed kilns, creating different chambers or spaces for combustion and for the pieces, playing with the location of heat sources, insulation, draught and the use of new fuels.

The evolution of kilns for ceramics in China, and later in Korea and Japan was on a separate and different path from that of Eurasia. Through gradual developments they achieved precise control and the attainment of high temperatures which put them far ahead of Europe, Africa and the Western Hemisphere during the long period from the end of the Neolithic period (around 1500 BC) to the beginning of the 18th century. Their greatest achievement was the production of translucent white porcelain impossible without the high firing temperatures they were able to achieve with their kilns.

JAPANESE CERAMIC TECHNIQUES

We believe that it deserves a special section to talk about some methods that we have inherited from the East and that are increasingly being used by artisans working with contemporary Western ceramics.

From Japan we receive aesthetic concepts based on a different philosophy and way of life, such as “opposites connect”, emptiness is an element in itself, the beauty of the imperfect and the “broken”, etc.

Let’s take a look at some of these Japanese ceramic techniques:

RAKU

It is a type of ceramic in itself. In this way of creating it, the firing process and a subsequent “reduction” treatment are of vital importance.

A clay that resists thermal shocks is used, it is baked at a not very high temperature (less than 1000º) and after the oven the piece goes directly to a place where there is combustible material (such as sawdust, paper, etc.) and it is covered. There, after the initial combustion, and having reduced the oxygen, a piece is obtained in which, after oxidation, magical effects and a certain metallic shine have appeared.

Read more about Raku

KURINUKI

It is a traditional technique of Japanese ceramics, it is a technique of casting on the piece that we have already made. To do this you can use one of the tools that are sold for this purpose, but any homemade element will do, such as a spoon.

Sometimes we see on the internet images of Kurinuki that show works in which we only look at the outer surface, the important thing here is the hollowing that is done to form the inside, the outer face has its additional work that can be done with other techniques, for example, it is very common to use here the faceted.

KINTSUGI

Consider the breakage and repair of the ceramic piece as part of its history, rather than something to disguise. The key to this Japanese technique of gluing broken pottery together is to repair it in an “ostentatious” manner where the beauty of the joints is proudly displayed. This idea is in keeping with the aesthetic concept of Wabi-sabi. For this purpose, materials are used that include shiny lacquers, with silver, gold and even platinum, in this sense it is related to “Maki-e” (a decorative technique that uses lacquers and metallic powder).

In the past, it was a way of passing a piece of pottery that had an accidental breakage to another “aesthetic state”, nowadays it is common to make the piece and then break it.

If you want to know more, you can read our post about Kintsugi.

All these techniques used in artistic ceramics that we have been dealing with and that you can expand little by little, would be part of the creative structure: the materials, the technical knowledge and the personal capacity and creativity.

The world of ceramics is very, very wide, each path you choose offers possibilities to develop a lifetime, so the advice is to savor it slowly and consciously.

(*) Text and images with the collaboration of Arantxa de Ceramicaespiral

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