Discover the secrets of pottery


Forming techniques

Pottery can be shaped by a rangespecific to flatware such as plates
techniques, including:whilst a similar technique, jolleying,
Handwork can be considered both the mostrefers to the production of holloware
primitive and the most individualizedlike cups. These techniques have been in
techniques, where pieces are constructeduse since at least the 18th century
from hand-rolled coils, slabs, ropes,Partial automation of the jiggering and
and balls of clay body, often joinedjolleying processes have long been used
with a slurry of clay body, known asto increased production rates and
slip. No two pieces of handwork will bede-skill the operation
exactly the same, so it is not suitableRoller-head Machine A machine for the
for making precisely matched sets ofshaping of pottery flatware on a
items such as dinnerware. Doing handworkrotating mould, as in a jigger, but with
enables the potters to use theira rotary shaping tool instead of a fixed
imagination to create one-of-a-kindprofile. The rotary tool is in the form
works of art. These methods are oftenof a shallow cone of the same diameter
referred to as "handbuilding".as the ware and shaped to produce the
Classic potter's wheel in Erfurt,back of the article being made. The ware
Germany.The potter's wheel. A ball ofis completely shaped, by relatively
clay body is placed in the center of aunskilled labour, in one operation at a
turntable, called the wheel head, whichrate depending on the size of the ware
is turned either using foot power (aof about 12 pieces per minute. The
kick wheel or treadle wheel) or amachine, developed from earlier attempts
variable speed electric motor.to improve on the use of a fixed tool,
Oftentimes, a bat (a disk of plastic,was patented by T. G. Green & Co. and H.
wood, or plaster) is affixed to theJ. Smith (Brit. Pat., 621 712, 14/4/49)
wheel head, and the ball of clay body iswith subsequent improvements by J. A.
attached to the bat rather than theJohnson (Brit. Pat., 765 097, 2/1/57;
wheel head so that the finished piece895 988, 9/5/62). It is now widely used
can be removed easily without distortingacross the world
the piece. The wheel is made to revolveRam Pressing A process for the plastic
rapidly while the body is pressed,shaping of tableware and sanitaryware by
squeezed, and pulled gently into shape.pressing a bat of the prepared body
The process of pressuring the body intobetween two porous plates or mould
a rotational symmetry, so that it doesunits; after the pressing operation, air
not move from side to side as the wheelis blown through the porous mould parts
head rotates is referred to asto release the shaped ware. Although the
"centering" the body — a mostprocess was patented in 1952 by Ram
important skill to master before theIncorporated, US Pats, 2 584 109 & 10,
next steps, "throwing" (forming andthe term is often used for similar type
raising the walls of the piece) andshaping processes
"trimming" or "turning" (removing excessGranulate pressing This involves the
clay to refine the shape or create ashaping of ware by compressing semi-dry
bottom or foot can be taken.and granulated body in a die, one side
Potter's wheels can be used for massof which is a solid surface and the
production, although often it isother a flexible membrane through which
employed to make individual pieces.fluid pressure, of up to 100 MN.m-2, is
Wheel work takes a lot of technicaltransferred. The granulate is produced
ability, but a skilled potter canby spray drying to give a fine and free
produce many virtually identical plates,flowing material with a low moisture
vases, or bowls in a day. Because of itscontent of around 5-6%. Also known as
nature, wheel work can only be used todust pressing the technique is widely
initially create items with radialused in manufacture of wall and floor
symmetry on a vertical axis. Thesetiles, and increasingly of plates
pieces can then be altered byTurning is similar to that used for the
impressing, bulging, carving, fluting,shaping of metal and wood articles. A
faceting, incising, and other methods toblank of clay body, with low water
make them more visually interesting.content in a condition known as
Often, thrown pieces are furtherleatherhard, is mounted on a lathe
modified by having handles, lids, feet,whilst a cutting tool follows a profile
spouts, and other functional aspectsto removes excess material and hence
added using the techniques ofleave a shaped article
handworking. Pottery that is thrown onSlipcasting is a technique often used
the wheel is often finished in a processfor mass-production, and ideally suits
known as trimming.shapes that can not be made by other
Jiggering & jolleying These can be seenmethods. Liquid clay body slip is poured
to be an extension of using a Pottersinto plaster moulds, the permeability of
wheel, and in comparison allow increasedthe mould drawing water from the slip to
speed and improved repeatability.leave a layer the clay body of the
Jiggering is the technique where ainternal shape of the mould. This method
shaped tool is slowly brought down ontois almost universally used for
plastic clay body that has been placedsanitaryware, toilets and wash basins,
on top of a rotating plaster mould. Theas well being widely used for smaller
jigger tool shapes one face whilst thepieces such as figurines which have many
mould the other. Jiggering is the termintricate details.



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