A slip is a clay

slurry A slurry is a mixture of denser solids suspended in liquid, usually water. The most common use of slurry is as a means of transporting solids or separating minerals, the liquid being a carrier that is pumped on a device such as a centrifugal pu ...

used to produce

pottery Pottery is the process and the products of forming vessels and other objects with clay and other raw materials, which are fired at high temperatures to give them a hard and durable form. The place where such wares are made by a ''potter'' is al ...

and other

ceramic A ceramic is any of the various hard, brittle, heat-resistant, and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcela ...

wares. Liquified clay, in which there is no fixed ratio of water and clay, is called slip or clay slurry which is used either for joining leather-hard (semi-hardened) clay

body Body may refer to: In science * Physical body, an object in physics that represents a large amount, has mass or takes up space * Body (biology), the physical material of an organism * Body plan, the physical features shared by a group of anim ...

(pieces of pottery) together by slipcasting with

mould A mold () or mould () is one of the structures that certain fungi can form. The dust-like, colored appearance of molds is due to the formation of spores containing fungal secondary metabolites. The spores are the dispersal units of the fungi ...

, glazing or decorating the pottery by painting or dipping the pottery with slip.What is slip in pottery
thepotterywheel.com, accessed 10 July 2021. Pottery on which slip has been applied either for glazing or decoration is called slipware. Engobe, from the French word for slip, is a related term for a liquid suspension of clays and

flux Flux describes any effect that appears to pass or travel (whether it actually moves or not) through a surface or substance. Flux is a concept in applied mathematics and vector calculus which has many applications in physics. For transport phe ...

, in addition to fillers and other materials. This is in contrast to slips, which are historically considered to be a liquid suspension of only clay or clays in water. Engobes are commonly used in the ceramic industry, typically to mask the appearance of the underlying clay body. They can be sprayed onto pieces in a similar method to glaze and through the addition of coloring oxides they can achieve a wide variety of colors, though not with the same vibrancy as glazes. Among artists engobes are often confused with slip, and the term is sometimes used interchangeably.

Usage

Joining and molding

An additive with deflocculant properties, such as

sodium silicate Sodium silicate is a generic name for chemical compounds with the formula or ·, such as sodium metasilicate (), sodium orthosilicate (), and sodium pyrosilicate (). The anions are often polymeric. These compounds are generally colorless tra ...

, can be added to disperse the raw material particles. This allows a higher solids content to be used, or allows a fluid to be produced with a minimal amount of water so that drying shrinkage is minimised, which is important during slipcasting. Usually the mixing of slip is undertaken in a blunger although it can be done using other types of mixers or even by hand. * To join sections of unfired ware or greenware, such as handles and spouts. * To fix into place pieces of

relief Relief is a sculpture, sculptural method in which the sculpted pieces remain attached to a solid background of the same material. The term ''wikt:relief, relief'' is from the Latin verb , to raise (). To create a sculpture in relief is to give ...

decoration produced separately, for example by moulding. This technique is known as '' sprigging''; an example is

Jasperware Jasperware, or jasper ware, is a type of pottery first developed by Josiah Wedgwood in the 1770s. Usually described as stoneware, it has an unglazed matte "biscuit" finish and is produced in a number of different colours, of which the most com ...

. * When slip is used to join two pieces of greenware together, it is generally used with a technique known as scratch and slip, whereby the contact points on both pieces are scored with multiple criss-crossing lines and slip painted on one piece over the scores.

Decoration and protection

Charger of Charles II in the Boscobel Oak LACMA M

Slipware is pottery decorated by slip placed onto a wet or leather-hard clay body surface by dipping, painting or splashing. Some slips will also give decreased permeability, though not as much as a

ceramic glaze Ceramic glaze, or simply glaze, is a glassy coating on ceramics. It is used for decoration, to ensure the item is impermeable to liquids and to minimize the adherence of pollutants. Glazing renders earthenware impermeable to water, sealing th ...

would give. Often only pottery where the slip creates patterns or images will be described as slipware, as opposed to the many types where a plain slip is applied to the whole body, for example most fine wares in

Ancient Roman pottery Pottery was produced in enormous quantities in ancient Rome, mostly for utilitarian purposes. It is found all over the former Roman Empire and beyond. Monte Testaccio is a huge mound, waste mound in Rome made almost entirely of broken amphorae u ...

, such as African red slip ware (note: "slip ware" not "slipware"). Decorative slips may be a different colour than the underlying clay body or offer other decorative qualities such as a shiny surface. Selectively applying layers of colored slips can create the effect of a painted ceramic, such as in the

black-figure Black-figure pottery painting (also known as black-figure style or black-figure ceramic; ) is one of the styles of Ancient Greek vase painting, painting on pottery of ancient Greece, antique Greek vases. It was especially common between the 7th a ...

red-figure pottery Red-figure pottery () is a style of Pottery of ancient Greece, ancient Greek pottery in which the background of the pottery is painted black while the figures and details are left in the natural red or orange color of the clay. It developed in A ...

styles of

Ancient Greek pottery Pottery, due to its relative durability, comprises a large part of the archaeological record of ancient Greece, and since there is so much of it (over 100,000 painted vases are recorded in the Corpus vasorum antiquorum), it has exerted a dispro ...

. Slip decoration is an ancient technique in Chinese pottery also, used to cover whole vessels over 4,000 years ago. Principal techniques include slip-painting, where the slip is treated like paint and used to create a design with brushes or other implements, and slip-trailing, where the slip, usually rather thick, is dripped onto the body. Slip-trailed wares, especially if Early Modern English, are called slipware. Chinese pottery also used techniques where patterns, images or calligraphy were created as part-dried slip was cut away to reveal a lower layer of slip or the main clay body in a contrasting colour. The latter of these is called the "cut-glaze" technique.Vainker, 116-117 Slipware may be carved or burnished to change the surface appearance of the ware. Specialized slip recipes may be applied to biscuit ware and then refired.

Barbotine wikt: barbotine, Barbotine is the French for slip (ceramics), ceramic slip, or a mixture of clay and water used for moulding or decorating pottery. In English the term is used for three different techniques of decorating pottery, though in all cas ...

(another French word for slip) covers different techniques in English, but in the sense used of late 19th-century art pottery is a technique for painting wares in polychrome slips to make painting-like images on pottery.

Other uses in pottery

A slip may be made for various other purposes in the production and decoration of ceramics, such as slip can be used to mix the constituents of a clay body.

Gallery

File:MET DP274692.jpg, Chinese

Cizhou ware Cizhou ware or Tz'u-chou ware () is a wide range of Chinese ceramics from between the late Tang dynasty and the early Ming dynasty, but especially associated with the Northern Song to Yuan period in the 11–14th century. It has been increasingl ...

vase with cut-glaze decoration File:Phenician plate with red slip 7th century BCE excavated in Mogador island.jpg,

Phoenicia Phoenicians were an Ancient Semitic-speaking peoples, ancient Semitic group of people who lived in the Phoenician city-states along a coastal strip in the Levant region of the eastern Mediterranean, primarily modern Lebanon and the Syria, Syrian ...

n plate with red slip, now wearing away, 7th century BC, excavated at Mogador Island near

Essaouira Essaouira ( ; ), known until the 1960s as Mogador (, or ), is a port city in the western Moroccan region of Marrakesh-Safi, on the Atlantic coast. It has 77,966 inhabitants as of 2014. The foundation of the city of Essaouira was the work of t ...

File:Miletus ware showig red clay base.jpg,

Miletus ware Miletus ware is a type of pottery that was produced in various locations in Anatolia between the late 14th and mid 15th centuries. The pottery type was excavated in quantity in the 1930s by Friedrich Sarre at Balat, Didim, ancient Miletus, hence ...

showing a red body covered by white slip, then painted in blue, c. 1400,

Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

References