Forming techniques

Pottery can be shaped by a range techniques,term specific to flatware such as plates whilst a
including:similar technique, jolleying, refers to the production
Handwork can be considered both the mostof holloware like cups. These techniques have
primitive and the most individualized techniques,been in use since at least the 18th century Partial
where pieces are constructed from hand-rolledautomation of the jiggering and jolleying processes
coils, slabs, ropes, and balls of clay body, oftenhave long been used to increased production
joined with a slurry of clay body, known as slip.rates and de-skill the operation
No two pieces of handwork will be exactly theRoller-head Machine A machine for the shaping of
same, so it is not suitable for making preciselypottery flatware on a rotating mould, as in a
matched sets of items such as dinnerware. Doingjigger, but with a rotary shaping tool instead of a
handwork enables the potters to use theirfixed profile. The rotary tool is in the form of a
imagination to create one-of-a-kind works of art.shallow cone of the same diameter as the ware
These methods are often referred to asand shaped to produce the back of the article
"handbuilding".being made. The ware is completely shaped, by
Classic potter's wheel in Erfurt, Germany.Therelatively unskilled labour, in one operation at a
potter's wheel. A ball of clay body is placed in therate depending on the size of the ware of about
center of a turntable, called the wheel head, which12 pieces per minute. The machine, developed
is turned either using foot power (a kick wheel orfrom earlier attempts to improve on the use of a
treadle wheel) or a variable speed electric motor.fixed tool, was patented by T. G. Green & Co.
Oftentimes, a bat (a disk of plastic, wood, orand H. J. Smith (Brit. Pat., 621 712, 14/4/49) with
plaster) is affixed to the wheel head, and the ballsubsequent improvements by J. A. Johnson (Brit.
of clay body is attached to the bat rather thanPat., 765 097, 2/1/57; 895 988, 9/5/62). It is now
the wheel head so that the finished piece can bewidely used across the world
removed easily without distorting the piece. TheRam Pressing A process for the plastic shaping of
wheel is made to revolve rapidly while the body istableware and sanitaryware by pressing a bat of
pressed, squeezed, and pulled gently into shape.the prepared body between two porous plates or
The process of pressuring the body into amould units; after the pressing operation, air is
rotational symmetry, so that it does not moveblown through the porous mould parts to release
from side to side as the wheel head rotates isthe shaped ware. Although the process was
referred to as "centering" the body — apatented in 1952 by Ram Incorporated, US Pats,
most important skill to master before the next2 584 109 & 10, the term is often used for
steps, "throwing" (forming and raising the walls ofsimilar type shaping processes
the piece) and "trimming" or "turning" (removingGranulate pressing This involves the shaping of
excess clay to refine the shape or create aware by compressing semi-dry and granulated
bottom or foot can be taken.body in a die, one side of which is a solid surface
Potter's wheels can be used for mass production,and the other a flexible membrane through which
although often it is employed to make individualfluid pressure, of up to 100 MN.m-2, is transferred.
pieces. Wheel work takes a lot of technical ability,The granulate is produced by spray drying to give
but a skilled potter can produce many virtuallya fine and free flowing material with a low
identical plates, vases, or bowls in a day. Becausemoisture content of around 5-6%. Also known as
of its nature, wheel work can only be used todust pressing the technique is widely used in
initially create items with radial symmetry on amanufacture of wall and floor tiles, and
vertical axis. These pieces can then be altered byincreasingly of plates
impressing, bulging, carving, fluting, faceting,Turning is similar to that used for the shaping of
incising, and other methods to make them moremetal and wood articles. A blank of clay body,
visually interesting. Often, thrown pieces arewith low water content in a condition known as
further modified by having handles, lids, feet,leatherhard, is mounted on a lathe whilst a cutting
spouts, and other functional aspects added usingtool follows a profile to removes excess material
the techniques of handworking. Pottery that isand hence leave a shaped article
thrown on the wheel is often finished in a processSlipcasting is a technique often used for
known as trimming.mass-production, and ideally suits shapes that can
Jiggering & jolleying These can be seen to be annot be made by other methods. Liquid clay body
extension of using a Potters wheel, and inslip is poured into plaster moulds, the permeability
comparison allow increased speed and improvedof the mould drawing water from the slip to leave
repeatability. Jiggering is the technique where aa layer the clay body of the internal shape of the
shaped tool is slowly brought down onto plasticmould. This method is almost universally used for
clay body that has been placed on top of asanitaryware, toilets and wash basins, as well
rotating plaster mould. The jigger tool shapes onebeing widely used for smaller pieces such as
face whilst the mould the other. Jiggering is thefigurines which have many intricate details.