Definition
History and Traditional Styles
Pottery Process
Ornamentation
Firing
Ceramics
Places to Display or Sell
Definition
Pottery is the ceramic ware made by potters. It
can also refer to the material of which the
pottery ware is made. Major types of pottery
include earthenware, stoneware, and porcelain.
The places where such wares are made are called
potteries. Pottery is one of the oldest human
technologies and art forms and remains a major
industry today. Ceramic art encompasses the art
of pottery, whether in items made for use or
purely for decoration. Pottery is made by
forming a clay body into objects of a required
shape and heating them to high temperatures in a
kiln to induce reactions that lead to permanent
changes, including increasing their strength and
hardening and setting their shape. There are
wide regional variations in the properties of
clays used by potters and this often helps to
produce wares that are unique in character to a
locality. It is common for clays and other
minerals to be mixed to produce clay bodies
suited to specific purposes.
History and Traditional Styles
When most people think of pottery, they think of
bowls and plates, or perhaps cups, vases, and
ashtrays. And it is true that the functional
forms of pottery may be the most common. But
archeologically, the study of pottery may also
allow inferences to be drawn about a culture's
daily life, religion, social relationships,
attitudes toward neighbors, attitudes to their
own world and even the way the culture
understood the universe. The earliest history
of pottery production can be divided into four
periods namely; the Hassuna period (5000 - 4,500
BCE), the Halaf period (4,500 - 4000 BCE), the
Ubaid period (4000 - 3000 BCE), and the Uruk
period (3,500 - 2000 BCE). Ceramics, itself,
dates back even farther, to the year 25,000 BCE,
with the discovery of a Venus figurine in the
modern-day Czech Republic. But it was the
invention of the potter’s wheel in Mesopotamia
sometime between 6,000 and 4,000 BCE (Ubaid
period) revolutionized pottery production.
Pottery Process
Shaping is done in various ways, but working
clay with the hands is always used at one point,
or another. The clay material is either built
up from a flat slab, a stack of coils, or balls
of clay to form the desired shape. A slurry
solution is added to smooth out unwanted bumps
and to help work out spaces of air. Working by
hand is the slowest method, but it is also the
most controlled means of producing size and
shape. Studio potters most often choose hand
shaping because it allows them to create unique
pieces.
“Throwing” refers to the process potters use
when a potter’s wheel is used. It involves
placing a ball of clay on a turntable that the
potter rotates with a stick, a foot-powered
treadle, or an electric motor. The throwing
wheel rotates rapidly and as it moves, the
potter presses out a center in the ball
(“centering”), gently hollowing out a center in
the clay (“opening”), making a flat or rounded
bottom inside the pot (“flooring”), drawing up
the sides so that they’re even and symmetrical
(“pulling”), and then removing excess clay to
make an even foot (“trimming”). Until the
introduction of slip casting in the 18th
century, the potter’s wheel was the most
effective method of mass producing pottery.
Because if its inherent limitations, wheel work
can only be used to create wares with radial
symmetry on a vertical axis. These can then be
altered by impressing, bulging, carving,
fluting, faceting, incising, and other methods,
making the wares more visually interesting.
Often, thrown pieces are further modified by
having handles, lids, feet, spouts, and other
functional aspects added using the techniques of
hand working. Shapes and textures can be added
through the use of paddles, rollers, knives,
wires, burnishing stones, and rasps.
Incidentally, prior to some shaping processes,
air trapped within the clay body needs to be
removed. This is called de-airing and can be
accomplished by a machine called a vacuum pug or
manually by wedging. Wedging can also help to
ensure even moisture content throughout the
body. Once a clay body has been de-aired or
wedged, it is shaped by a variety of techniques.
After shaping it is dried before firing. There
are a number of stages in the drying process.
Leather-hard refers to the stage when the clay
object is approximately 75-85% dry. Clay bodies
at this stage are very firm and only slightly
pliable. Trimming and handle attachment often
occurs at the leather-hard state. Clay bodies
are said to be "bone-dry" when they reach a
moisture content at or near 0%. Unfired objects
are often termed greenware. Clay bodies at this
stage are very fragile and hence can be easily
broken.
Following is a list of other pottery methods
(other than hand-shaping or the potter’s wheel):
Granulate pressing: As the name suggests, this
is the operation of shaping pottery by pressing
clay in a semi-dry and granulated condition in a
mould. The clay is pressed into the mould by a
porous die through which water is pumped at high
pressure. The granulated clay is prepared by
spray-drying to produce a fine and free flowing
material having a moisture content of between
about five and six per cent. Granulate pressing,
also known as dust pressing, is widely used in
the manufacture of ceramic tiles and,
increasingly, of plates.
Jiggering and jolleying: These operations are
carried out on the potter's wheel and allow the
time taken to bring wares to a standardized form
to be reduced. Jiggering is the operation of
bringing a shaped tool into contact with the
plastic clay of a piece under construction, the
piece itself being set on a rotating plaster
mould on the wheel. The jigger tool shapes one
face while the mould shapes the other. Jiggering
is used only in the production of flat wares,
such as plates, but a similar operation,
jolleying, is used in the production of
hollow-wares, such as cups. Jiggering and
jolleying have been used in the production of
pottery since at least the 18th century. In
large-scale factory production jiggering and
jolleying are usually automated, which allows
the operations to be carried out by semi-skilled
labor.
Roller-head machine: This machine is for shaping
wares on a rotating mold, as in jiggering and
jolleying, but with a rotary shaping tool
replacing the fixed profile. The rotary shaping
tool is a shallow cone having the same diameter
as the ware being formed and shaped to the
desired form of the back of the article being
made. Wares may in this way be shaped, using
relatively unskilled labor, in one operation at
a rate of about twelve pieces per minute, though
this varies with the size of the articles being
produced. Developed in the UK just after World
War II by the company Service Engineers
roller-heads were quickly adopted by
manufacturers around the world; they remain the
dominant method for producing flatware.
Pressure casting: Specially developed polymeric
materials allows mould to be subject to
application external pressures of up to 4.0 MPa,
and so much higher than slip casting in plaster
moulds where the capillary forces correspond to
a pressure of around 0.1 - 0.2 MPa. The high
pressure leads to much faster casting rates, and
hence faster production cycles. Furthermore, the
application of high pressure air through the
polymeric molds upon de-molding, the cast means
a new casting cycle can be started immediately
in the same mold, unlike plaster molds which
require lengthy drying times. The polymeric
materials have much greater durability than
plaster and, therefore, it is possible to
achieve shaped products with better dimensional
tolerances and much longer mould life. Pressure
casting was developed in the 1970s for the
production of sanitary ware, although more
recently it has been applied to tableware.
RAM pressing: A factory process for shaping
table wares and decorative ware by pressing a
bat of prepared clay body into a required shape
between two porous molding plates. After
pressing, compressed air is blown through the
porous mold plates to release the shaped wares.
Slip Casting: Is often used in the
mass-production of ceramics and is ideally
suited to the making of wares that cannot be
formed by other methods of shaping. A slip, made
by mixing clay body with water, is poured into a
highly absorbent plaster mold. Water from the
slip is absorbed into the mould leaving a layer
of clay body covering its internal surfaces and
taking its internal shape. Excess slip is poured
out of the mold, which is then split open and
the molded object removed. Slip casting is
widely used in the production of sanitary wares
and is also used for making smaller articles,
such as intricately detailed figurines.
Ornamentation
Pottery can be decorated in an almost limitless
number of ways. The clay can be incised (cut
with a wedged object to make a three dimensional
pattern), it can be decorated with an underglaze,
it can use in-glaze or on-glaze decoration, and
it can be enameled. You can use additives to
your piece, such as sand, differently colored
clays, and colorants, such as metal oxides or
carbonates. Combustible particles, such as salt
or sulfur, can be pressed into the clay’s
surface to produce striking textures, once the
pottery has been fired. Agateware results from
banding different clays together in order to
produce the mottled or veined appearance of
agate. Banding, or lining, adds a color to the
edge of a plate or cup and is usually done while
the piece is still on the potter’s wheel.
Burnishing refers to an application where the
surface of a piece is rubbed with wood, steel or
stone before it is fired. When fine clays are
used with the burnishing process, a highly
polished surface will result. An engobe is a
whitish slip of clay that can be added before
firing; it can be painted on or dipped to
provide a uniform, even coat. If it is used in
several coats, it resembles a glaze. A litho
(or transfer print) can be used on the pottery.
This involves three layers—the actual image
layer, the cover coat, and the clear, protective
layer. Gold can be added to high quality
objects by various means, such as painting,
etching, a “bright gold” solution, or a rubbing
of gold leaf with sugar and salt.
A glaze is the “glassy” part of ornamentation on
a piece of pottery. It is also the process that
waterproofs it. It can be accomplished by
dusting, spraying, dipping, or brushing with a
mineral/water mixture. The color of a glazed
piece before and after firing may differ. An
additional piece of advice is to either not
glaze the foot portion of the piece or use
little supports (spurs) inside the kiln so that
the piece doesn’t stick to the rack during the
firing process.
Firing
Firing is what makes a piece of dried clay
pottery. As a rough guide, earthenwares are
normally fired at temperatures in the range of
about 1000 to 1200 degrees Fahrenheit;
stonewares at between about 1832 to 2372 degrees
Fahrenheit; and porcelains at between about 2192
to 2552 degrees Fahrenheit. The atmosphere
within a kiln during firing can affect the
appearance of the finished wares. An oxidizing
atmosphere, produced by allowing air to enter
the kiln, can cause the oxidation of clays and
glazes. A reducing atmosphere, produced by
limiting the flow of air into the kiln, can
strip oxygen from the surface of clays and
glazes. This can affect the appearance of the
wares being fired and, for example, some glazes
containing iron fire brown in an oxidizing
atmosphere, but green in a reducing atmosphere.
The atmosphere within a kiln can be adjusted to
produce complex effects in glaze.
Kilns may be heated by burning wood, coal and
gas, or by electricity. When used as fuels, coal
and wood can introduce smoke, soot and ash into
the kiln which can affect the appearance of
unprotected wares. For this reason wares fired
in wood- or coal-fired kilns are often placed in
the kiln in saggars; lidded ceramic boxes, to
protect them. Modern kilns powered by gas or
electricity are cleaner and more easily
controlled than older wood- or coal-fired kilns
and often allow shorter firing times to be used.
In a Western adaptation of traditional Japanese
Raku ware firing, wares are removed from the
kiln while hot and smothered in ashes, paper or
woodchips, which produces a distinctive,
carbonized, appearance. This technique is also
used in Malaysia in creating traditional labu
sayung.
Ceramics
A ceramic is an inorganic, non-metallic solid
prepared by the action of heat and subsequent
cooling. Ceramic materials may have a
crystalline or partly crystalline structure, or
may be amorphous (e.g., a glass). Because most
common ceramics are crystalline, the definition
of ceramic is often restricted to inorganic
crystalline materials, as opposed to the
non-crystalline glasses. “Ceramic” may be used
as an adjective describing a material, product
or process; or as a singular noun, or, more
commonly, as a plural noun, ceramics. In
contemporary, domestic terms, ceramics takes on
a specific form of hobby, mainly the painting
and ornamentation of greenware, usually
pre-formed into all sorts of vases, plates,
bowls, figurines, etc. For nominal fees, art
studios or recreational centers allow the public
to come in and paint a piece or two and then
return a week later, after firing, to glaze and
add any other effects.
The earliest ceramics were pottery objects made
from clay, either by itself or mixed with other
materials, hardened in fire. Later ceramics were
glazed and fired to create a colored, smooth
surface. Ceramics now include domestic,
industrial and building products and art
objects. In the 20th century, new ceramic
materials were developed for use in advanced
ceramic engineering; for example, in
semiconductors.
The earliest evidence of glazed brick is the
discovery of glazed bricks in the Elamite Temple
at Chogha Zanbil, dated to the 13th century BC.
Glazed and colored bricks were used to make low
reliefs in Ancient Mesopotamia, most famously
the Ishtar Gate of Babylon (ca. 575 BC), now
partly reconstructed in Berlin, with sections
elsewhere. Mesopotamian craftsmen were imported
for the palaces of the Persian Empire, such as
Persepolis. The tradition continued, and after
the Islamic conquest of Persia, colored and
often painted glazed bricks or tiles became an
important element in Persian architecture, and
from there spread to much of the Islamic world,
notably the İznik pottery of Turkey under the
Ottoman Empire in the 16th and 17th centuries.
Transmitted via Islamic Spain, a new tradition
of Azulejos developed in Spain and especially
Portugal, which by the Baroque period produced
extremely large painted scenes on tiles, usually
in blue and white. Delftware tiles, typically
with a painted design covering only one (rather
small) tile, were ubiquitous in Holland and
widely exported over Northern Europe from the
16th century on. Several 18th century royal
palaces had porcelain rooms with the walls
entirely covered in porcelain. Surviving
examples include ones at Capodimonte, Naples,
the Royal Palace of Madrid, and the nearby Royal
Palace of Aranjuez. Elaborate tiled stoves were
a feature of rooms of the middle and
upper-classes in Northern Europe from the 17th
to 19th centuries.
There are several other types of traditional
tiles that remain in manufacture, for example
the small, almost mosaic, brightly colored
zellige tiles of Morocco. With exceptions,
notably the Porcelain Tower of Nanjing, tiles or
glazed bricks do not feature largely in East
Asian ceramics.
That doesn’t mean, however, that there wasn’t
ceramic work being done in East Asia. In the
Yuchanyan Cave in Hunan, China, yielded shards
of ceramic vessels and other artifacts which
were dated by analysis of charcoal and bone
collagen, giving a date range of 17,500 to
18,300 years old for the pottery. The pottery
specimens may be the oldest known examples of
pottery anywhere in the world, and provide some
of the earliest evidence for pottery making in
China. Pottery which dates back to 10,000 BC has
also been excavated in China.
In Japan, the earliest known pottery vessels
were thought to be those made by the Incipient
Jōmon (the term "Jōmon" means "cord-marked" in
Japanese and refers to the markings made on clay
vessels and figures using sticks with cords
wrapped around them). These people lived around
10,500 BC.
From the eighth to eighteenth centuries, glazed
ceramics was important in Islamic art, usually
in the form of elaborate pottery, developing on
vigorous Persian and Egyptian pre-Islamic
traditions, in particular. Tin-opacified glazing
was developed by the Islamic potters; the first
examples of blue-painted ware were in Basra,
dating from about the 8th century. The Islamic
world had contact with China and increasingly
adapted many Chinese decorative motifs. Persian
wares gradually relaxed Islamic restrictions on
figurative ornament, and painted figurative
scenes became very important.
Some of the better-loved, contemporary
collectible types of ceramics include Delftware,
Royal Doulton, bone china, and Wedgwood.
Places to Display or Sell
Now (returning to the 21st century), once you
find a style you’re happy with and successful at
reproducing, you can begin to look for
galleries, bookstores, or nooks at art co-ops
where you can stash a few of your pieces. See
what the public finds pleasing enough to buy and
take home. If you are lucky enough, you might
be commissioned to customize some pieces for a
local business or festival. If you can’t find a
suitable gallery to expose your work to the
public, consider creating an attractive website
with good quality images. Be sure to photograph
the unique colors or angles that you worked so
hard to create. Then make sure to generate
interest (and “hits”) to the website to get your
page among the first displayed when someone
Googles on the word “pottery” or “pottery
gallery.” Many artists do this with their
portfolios, and with good results. Visit their
websites and take note of their prices so that
you can list comparable prices. Your goal
should be to become recognized for your original
style. Whether or not you’ve had any luck on
the internet, try other approaches. If your
friend has a show room or warehouse, ask for a
chance to hold a special showing where your
“wares” might be featured. Most friends in such
businesses will see this as a good opportunity
to expose new people to their items or products,
too. This is another good chance to distribute
your business cards (with your online gallery’s
address included, of course).
It suffices to say that even knowing all about
the processes of basic pottery or ceramics
doesn’t actually mean anything until you’re
physically working on a piece from the bottom up
(if you’re molding using a potter’s wheel) or
the top down (if you’re glazing or painting
ceramics). The good thing about using coils of
clay or a simple ball is that you can always
pound the shape back into nothing if you don’t
like what you’re seeing. A single piece of clay
can undergo dozens of iterations before you find
something aesthetic; it’s a very necessary part
of the art. You may find out the hard way that
certain glazes won’t work over certain types of
paint, or that your piece was too narrow in a
certain area to withstand a particular heat
setting or method used in the kiln. Keep
experimenting—it is the heart and soul of every
great artist.
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Although it may seem more
intimidating to get into, once you learn the
basics and get some materials it is very
easy to continue and learn. Practically
anything can be made in ceramics,
from sculptures of people and animals, to
objects such as model houses, cars,
furniture. The trick to have fun while you
make it and not be afraid to make mistakes
and try new objects.
