QUALITY The classification of the quality of pottery ware is given in the six grades of fault:
- BEST - First quality pottery. Good ware. Sometimes called FIRSTS. But there is no such thing as a perfect pot since every piece will always have some sort of slight blemish since this is the very nature of pottery.
- BEST SECOND - Not bad enough to be a SECOND and not good enough to be BEST
- SECONDS - Imperfect pottery. Not BEST and not THIRDS or LUMP ! Slightly blemished or faulty and sold at a slight discount.
- WORST SECONDS - Sometimes called WORSER SECONDS - Slightly more imperfect than SECONDS. Then there was a DEGREE WORSER which was worse that WORST SECONDS. Or even WORSER WORSER. But not THIRDS, just yet.
- THIRDS - This signifies that the ware is well below the usual BEST standard, and not even good enough to fall within the description of SECONDS. But better than LUMP. The ware is still marketable however and was sold off to hawkers or market stall holders for sale on the 'stones'. Badly twisted ware, crooked holloware, nipped ware and whirler plates fall into this category.
- LUMP - Massively faulty pottery. So bad that it is worse than WORSER SECONDS. Or even THIRDS. This is the lowest quality of ware that leaves any potbank, and usually it is ware that has just managed to escape being deliberately smashed. Whilst there may have been possibilities in some china shops of disposing of SECONDS, or even THIRDS the risk of dealing in LUMP is "too great to be incurred lightheartedly." High-grade manufacturing firms see to it that LUMP is sent to the shraff tip, "in spite of the fact that enquiries were freely received from the poorer districts or export for mixed grades of lump." Usually, about 100 years later, it re-appears on TV shows as 'rare and valuable.' Irony!
- PITCHER Worse than lump. To be thrown away. Broken. Useless. But strangely saleable, at a price, in some quarters!
Also note this additional description of faulty pot: CRACK CRACKED and SOUND CRACKED Pottery which was found to be cracked after its glost firing was usually scrapped as useless. It was described as LUMP or PITCHER and usually sent to the shraff tip. However, some entrepreneurs in the industry were able to make money from selling cracked pottery - depending on how cracked it really was! Here, to explain is a quote from Brian Milner. He was one of those entrepreneurs in the 1960s, 70s and 80s. "We used to buy China teacups from Ridgways. These were termed "crack cracked" and "sound cracked". I am not kidding. They were [packed] 40 dozen in a teachest and we used to buy about 12 chests every 2 weeks. We would sound every one of the "crack cracked" and find a lot of sound ones which we used to decorate and we were still able to sell the really cracked to market men."
QUARL Fireclay slabs used to cover vents in the crown of the downdraught beehive kiln. When removed, after the firing, they speeded cooling. Like dampers on a bottle oven crown.
QUARTERS Part of a bottle oven. Areas within the bottle oven. The circular oven divided into four, or more.
QUARTER DAMPERS Part of a potter's bottle oven. A substantial and robust hinged brick and iron flap operated by iron levers and pulleys to close or open the hole in the domed roof (or crown) of the oven to control the flow of the hot combustion gases passing through the oven during firing. Four (or more depending on the size of the oven) quarter dampers were positioned equidistant around the circumference of the oven crown. Not to be mistaken with the crown damper which was the one in the top centre of the dome or crown of the oven.
|Quarter damper on the crown of a bottle oven.|
QUARTZ Mineral used in the pottery body recipe.
QUARTZ INVERSION Abrupt expansion in heating and corresponding contraction in cooling, which occurs in silica crystals in all clay and glazes at around 570°C. The room-temperature form of quartz, α-quartz, undergoes a reversible change in crystal structure at 573°C to form β-quartz. This phenomenon is called an inversion, and for the α to β quartz inversion is accompanied by a linear expansion of 0.45%. This inversion can lead to cracking of ceramic ware if cooling occurs too quickly through the inversion temperature. This is called dunting, and the resultant faults as dunts. To avoid such thermal shock faults, cooling rates not exceeding 50°C/hour are used by potters.
QUEEDLE Dialect. See-saw in a childrens' play ground. Health and safety risk! A long, narrow board pivoted in the middle so that, as one end goes up, the other goes down. Also used by adults, to the concern of the 'parkie' (park keeper.)
QUEENSWARE Type of pottery with a particular recipe and requiring particular firing conditions. Earthenware. Porous. Particular to Josiah Wedgwood. Branded. Type of creamware. Pale cream in colour throughout the body.
QUICKSILVER Material. The liquid metal - mercury. The only metal that is liquid at standard conditions for temperature and pressure.
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RAKU Type of firing process. Relatively low-temperature firing process inspired by traditional Japanese raku firing. Now usually involves removing the pot from the kiln while at bright red heat and placing it into containers with combustible materials such as paper or sawdust. Once the materials ignite, the containers are closed. This produces a highly reducing (reduction) atmosphere which affects the colors in glazes on the pottery surface and clay bodies. The drastic thermal shock also causes the glaze to craze (sometimes known as crackling since it is deliberate.)
RAMMLE Dialect. A non pedigree dog. A mongrel. Possibly a bit rough looking round the edges and poorly trained. Roughly, and almost but not entirely the exact opposite of a pooch.
RAISED AND CUT UP
Decorating department. Type of very expensive applied decoration. This term may be peculiar to the Spode Factory in Stoke on Trent, Staffordshire, England. The following is an extract from Robert Copeland's book, published by The Northern Ceramic Society in 2009. "Manufacturing Processes of Tableware during the Eighteenth and Nineteenth Centuries. more>
The Raised Spot
A small amount of raised paste powder, consisting mainly of china clay is put onto a tile and mixed with small amounts of turpentine using a pallet knife to blend them together to make a smooth paste. The paste then will be stiff so small amounts of fat oil are added until the mixture moves slightly, and this is when it is ready for spotting to be done. If the mixture is still too stiff the spot will have a sharp point, so more mixing will be needed. The spot is applied with a brush.
The paste is mixed as above described but is more mature; a slightly stiffer mixture than for spotting. The paste is shaped to the design and then tapered down with a wash of turps and the paste allowed to dry. With this style of raising 'cutting up' is usually applied onto the dry paste before firing. The paste for cutting up is old raised paste mixed with fat oil; it needs to be made very stiff by breathing on it, then gradually soften it until a stroke can be pulled out using a very fine sable brush. The raised paste is ﬁred and later gilded over.
RAISED GOLD or RAISED GILDING
sometimes known as RAISED AND SPOTTED or RAISED PASTE
Decorating department. Type of applied decoration. A gold pattern raised appreciably above the surface of the piece. This is a complicated and very expensive process using a paste (comprising flux, yellow colour and finely ground china wasters) to build up the required design in raised relief. Application was by hand using a fine camel hair brush, known as a pencil. This was then allowed to dry slowly to prevent cracking, fired at relatively low temperature, then gilded and followed by a further firing before the final burnishing brought out the soft golden glow of the real gold.
RAISED PASTE Type of applied decoration. The material used by the raised paste gilder to create the raise relief decoration. See Raised Gold or Gilding. Raised paste is a mixture based on china clay. It is applied onto a pre-gilded and pre-fired pottery surface. Sometimes the raised paste is modelled finely into an elaborate decoration. It is then fired and then coated with gold before another firing and then burnished with fine sand.
RAISED PASTE GILDER Occupation. Decorating department. Highly skilled and very well paid. The person who applies the raised paste and who covers it in gold after its firing.
RATTENING Vandalism! Destruction of pottery making equipment. An obsolete word meaning to sabotage, especially used during an industrial dispute. A Burnley newspaper of 1879 reported that at Church's, a Burslem Earthenware manufacturer, rattening was carried out in 1879.
RAVENSTONE Type of glaze with a particular recipe and requiring particular firing conditions. Matt black surface finish. Particular to Josiah Wedgwood. Branded.
RAWNGED Dialect. A particular manoevre of the body which is un-natural and therefore causes some discomfort, and even pain in the muscles. Or the cause of a back back. Straining.
REARING Process. Not to be confused with dottling. Placing glazed pottery flatware on vertically on their edges using thimbles and stilts, ready for glost firing in saggars.
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RECIPES of POTTERY BODIES
Adamant Brand name of Twyfords Sanitaryware. "Enamelled" Fireclay. Refractory buff coloured clay body with a white vitreous enamelled surface and fired to a very high temperature. It was thick and very strong and would withstand rough usage. Very large pieces were made with this recipe.
Agate Ware, Onyx Ware, Marbled Ware All earthenware made to imitate these various natural materials by mixing coloured clays and glazing with a soft rich glaze. These types were popular in England during the 18th century, and Josiah Wedgwood, FRS produced many varieties especially during his partnership with Whieldon (1754-9).
Alpine Pink Self-coloured Pink fine bone china introduced by Josiah Wedgwood and Sons Ltd in 1936
Bamboo ware A bamboo-like type of cane ware somewhat dark in colour, first made by Josiah Wedgwood in 1770.
Belleek Ware A distinctive type of pottery made at Belleek, County Fermanagh, Northern Ireland. The factory was established in 1857 and the ware is characterized by its thinness and slightly iridescent surface; the body contains a significant proportion of frit.
Black Basalt Stoneware. Brand of Josiah Wedgwood and Sons. Name given to self-coloured hard vitreous stoneware which can be polished on the lapidary wheel. Introduced by Josiah Wedgwood and others. Black and vitreous. Contains iron oxide and manganese dioxide. Introduced in 1776/1768 by Josiah Wedgwood. The body is black and vitreous, iron oxide and manganese dioxide being added to achieve this. Perfected by Josiah Wedgwood, FRS in 1776.
- 47% ball clay
- 3% china clay
- 40% ironstone
- 0% MnO
Boccaro Ware Red, unglazed stoneware with relief decoration.
Bone China Fine white ware composed of bone ash (to give translucency), china clay (or kaolin to give whiteness) and Cornish Stone (or felspar, to give strength). Translucent. Developed by the Spode Company around 1800. Known for its high whiteness and translucency, and very high mechanical strength and chip resistance. Fired to biscuit at 1260°C and fired for glost at 1060°C
- 50% animal bone (thigh bones of ox are best)
- 25% china clay (kaolin)
- 25% china stone (felspar)
Bit Clay A particular pottery body recipe. "Common moca body or dirty clay from the common bank" Possibly used in a similar way to bitstone.
Cane ware Stoneware made from clays that fire a range of shades from buff color to a pale yellowy-brown. The designation is derived from the cane-like colour of the ﬁnished ware. One of the earliest of the stonewares made to produce wares in the classical taste, it was introduced in the 1770s becoming less popular in the 19th century. Pieces were usually unglazed except for the interior of tablewares, and occasionally were decorated with painted enamel colors. Both dense and lighter canewares are produced in pottery, to accommodate various requirements. Some canewares supplied in table articles are much esteemed.
Celadon Self-coloured fine earthenware in which the colour permeates throughout the clay. Celadon was first produced in 1805.
Ceramant Brand name of Twyfords Sanitaryware. A vitreous china. Twice fired. A white vitreous (non porous) clay body of very fine texture with a glazed white or coloured surface. The clay was vitrified in the firing process so that to all intents and purposes it was non porous and would not absorb moisture. It was denser and stronger than earthenware of the same thickness but more expensive. Withdrawn.
Creamware Earthenware. Porous. Pale cream in colour throughout the body. Cream colored earthenware was developed in the 1740s. It was made principally from white firing ball clays found in Devon and Dorset. The lead used for the glaze was naturally contaminated with iron which imparted a golden tint to the glaze in shades. Creamware was refined and improved until by the 1760s it was suitable for making fashionable, elegant tableware. See also tortoiseshell and colored glazes.
Delftware or Delft pottery. Blue and white pottery made in and around Delft in the Netherlands and the tin-glazed pottery made in the Netherlands from the 16th century. Delftware has a white glaze and is usually decorated with metal oxides. Delftware includes pottery objects of all descriptions such as plates, ornaments and tiles.
Duramant Brand name of Twyfords Sanitaryware. Heavy Earthenware. Similar to Vitromant but thicker and stronger. Now withdrawn but in its time it was worth a small extra cost where increased strength was desirable.
Earthenware Type of pottery with a particular recipe and requiring particular firing conditions. White or cream coloured. Opaque. Porous with water absorption in the range 6-8%. Glazed to render it impervious to liquids.Earthenware is not translucent like Bone China or some Porcelain bodies (does not allow light to pass through it.) The first or biscuit firing temperature is 1100°C to 1150°C, glost firing 1050°C to 1100°C. There are several types of earthenware, including Creamware, Delftware, Faience, Tin-glazed pottery, Victorian majolica, Raku and Terra cotta.
- 25% china clay
- 25% ball clay
- 35% flint
- 15% china stone
Electrical Porcelain Type of porcelain used for producing electrical insulators.
- 30% ball clay
- 20% china clay
- 25% quartz
- 25% feldspar
Engobe Material used during the process. An intermediate layer. Usually a coloured clay mixed with water to create a thin clay slip. Can be used as decoration either under or on top of the glaze before firing. Can also be used to mask undesirable features in the clay to which it is applied. Common on the manufacture of fireclay sanitaryware as a white intermediate layer - like undercoat.
The engobe contains:
- 5 - 15% ball clay
- 30 - 50% china clay
- 15 - 30% ﬂint
- 20 - 35% china stone
- 0 - 10%, feldspar; the proportions of china stone and feldspar vary inversely as one another.
Faience Glazed ceramic ware, in particular decorated tin-glazed earthenware of the type which includes delftware and maiolica. French term for earthenware. Buff or pale red colour body glazed white to give an appearance of porcelain. Sometimes the name for architectural pottery.
Fine Fireclay 'Modern' fireclay is a blend of refined refractory ball clays and grog. When these clays are used to produce sanitaryware, the resultant product has a comparatively thick body of sufficient strength to withstand constant rough treatment. The body of Fine Fireclay is buff coloured and this is coated with a white ceramic undercoat called engobe which, in turn, is coated with two coats of glaze. The glaze is tough and vitreous.
Finestone Vitreous and opaque pottery body. A Spode brand and a Spode recipe developed from the Spode's Stone China body. The recipe contains a high percentage of alumina.
Fireclay (Sanitary Fireclay) Refractory buff coloured clay body with a white vitreous enamelled surface and fine to a very high temperature. It is thick and very strong and will withstand rough usage. Very large pieces can be made in this ware. The ceramic of choice for manufacturing very large ceramic pieces. Here, the classic ceramic mass is stabilised with the addition of pre-fired clay (grog or chamotte) which enables large ceramic pieces such as urinal slabs, sinks, mortuary slabs, double washbasins or floor-standing washbasin pedestals to be produced.
- 60 - 80% ﬁreclay
- 20 - 40% grog
Granite Ware Name used for hard, semi-vitrified earthenware. Popular in the US.
Ironstone or Ironstone China Vitreous, dense and hard pottery first made in the UK in the late 1700s/early 1800s A variety of earthenware but similar to stoneware. MASONS IRONSTONE Particular to Masons Pottery factory, Hanley. Hard, and granite-like of exceptional strength. The body of ironstone ware is particularly dense, for the reason, probably, that it contains a greater amount of Cornish stone than the majority of ordinary earthenwares. Doesn't contain iron or ironstone.
Ivory Body Cream-coloured ware which retains the ivory tint that is imparted to it by the ball clay. (Many earthenware bodies are artificially whitened by the addition of a cobalt blue stain)
Jasper Unglazed and hard vitreous stoneware stained with the addition of metallic oxides to create a variety of coloured bodies. With white or coloured embossed ornamentation sprigged onto the surface. Josiah Wedgwood became famous for it when he introduced it in 1774 but other potters also manufactured this type of ware. Thinly potted Jasper can sometimes be translucent. I
Jet Ware Type of pottery with a particular recipe and requiring particular firing conditions. Red clay body with black manganese-type glaze. A twin term to Rockingham. Jet wares were at one time extensively made in the Staffordshire Potteries and were often elaborately decorated. Jet teapots were popular in strictly plain shapes with little or no decoration. Jet is recognised as a very suitable body to employ for teapot manufacture, possessing a variety of suitable qualities.
Lavender Self-coloured fine earthenware in which the colour permeates throughout the clay. First produced by Wedgwood in 1850.
Maiolica Italian tin-glazed pottery dating from the Renaissance. It is decorated in bright colours on a white background, frequently depicting historical and legendary scenes.
Majolica Earthenware made in imitation of Italian maiolica, especially in England during the 19th century. Covered with soft, richly coloured glazes made famous by Italian potters in the 15th century.
Microlite Brand name for FINE FIRECLAY. A particular recipe of blended ball clays and grog to create a relatively fine, porous yet strong, clay used for the manufacturer of heavy sanitaryware.
Pearlware An earthenware with a body similar to early creamware, but with some cobalt stain added to the glaze to whiten it (actually it looks pale grey).
Plumbago Name of a refractory body recipe. Mixture of fireclay and graphite. Used extensively for the manufacture of crucibles for metal foundries. Made in the UK by Doulton & Co., Lambeth
Porcelain General name of a vitreous (non porous) and translucent, resonant ceramic 'whiteware.'
Smooth textured and white (pale grey) firing. Two types of porcelain are made:
- Hard paste porcelain is fired to temperatures in excess of 1400°C. Hard paste porcelain consists
- 40 - 50% china clay
- 20 - 30% feldspar
- 15 - 25% quartz (silica)
- After a low biscuit fire of about 900°C is glazed and the fired hard (high temperature) at 1400°C.
- Soft paste porcelain is fired to approx 1250°C. Soft paste porcelain is sometimes described as 'artificial' and contains pre-formed glassy substances. Soft paste is difficult to manufacture.
Porcelaineous White-firing stoneware body closely related to porcelain.
Queensware Earthenware. Porous. Particular to Josiah Wedgwood. Type of creamware. Josiah Wedgwood perfected this earthenware in 1762.
Redclay Component of pottery body recipe. Etruria marl. Traditionally used for potting teapots and floor tiles.
Redware Type of pottery with a particular recipe and requiring particular firing conditions. Can be porous in nature or highly vitrified.
Rockingham A coarse earthenware body made from red-burning clay. The Rockingham Pottery was a 19th-century manufacturer of porcelain and earthenware. Fine wares and ornamental pieces as well as manufacturing items for ordinary everyday use. Similar to Jet Ware.
Samian Was extensively produced in the North Staffordshire Potteries by teapot manufacturers. Common red ware, lacking in interest unless relieved by some sort of applied decoration. Similar to Jet and Rockingham, and suitable for the production of teapots and associated products. Slip-banded decorations, in a big variety of colours, are largely resorted to in order to make the Samian wares rather more interesting in appearance.
Sanitary Earthenware A type of sanitaryware made from white ﬁring clays but often covered with a coloured glaze. The body itself has a water absorption of 6 to 8% (See Vitreous China, below). May be once or twice ﬁred, at about 1120°C
The body is made from a recipe containing
- 22 - 24% ball clay
- 24 - 26% china clay
- 15 - 18% china stone
- 33 - 35% ﬂint
- 60 - 80% ﬁreclay
- 20 - 40% grog
- 5 - 15% ball clay
- 30 - 50% china clay
- 15 - 30% ﬂint
- 20 - 35% china stone
- 0 - 10%, feldspar; the proportions of china stone and feldspar vary inversely as one another.
SaphirKeramik Brand name for sanitaryware ceramic made by Laufen or Switzerland. Ceramic recipe with the addition of the mineral corundum, a component of sapphire. SaphirKeramik is considerably harder and has a greater flexural strength. SaphirKeramik is a new generation ceramic material that can generate completely new sanitaryware shapes. Closely defined radii and edges are now possible akin to those seen in pieces constructed from solid surfaces, along with much thinner walls making each ceramic piece up to 40% lighter than if it were made with traditional ceramic sanitaryware materials.
Semi-porcelain A lightweight earthenware, midway in its general characteristics between a full earthenware and a china body. Sometimes not so opaque as ordinary general earthenware, owing to its larger percentage of Cornish stone and because it was more thinly and delicately potted than the norm.
Clay recipe in the 1820s was:
- 16 pail full Black Clay Slip
- 2 pail full Flint
Stoke China Type of pottery with a particular recipe and requiring particular firing conditions. A particularly 'old' term peculiar to the Spode Factory. Bone china.
Stone China A hard and dense opaque feldspathic pottery.
Stoneware There is a great variety of stonewares. Vitreous, hard, strong and opaque. Quite heavy. Originally a single unblended naturally occurring clay but today blended clays make the recipe more stable and a little more predictable. Often buff coloured and containing a highly plastic ball clay which is naturally vitrifying at usual firing temperatures. A popular body used by craft potters. Sometimes salt glazed. Usually biscuit fired between 1180°C and 1280°C
Terracotta A type of fired clay, typically of a brownish-red colour and unglazed, used as an ornamental building material, garden vases and furniture, and in modelling. Sometimes salt glazed.
Vitreous China The pottery body recipe favoured today as the material from which the main items in the bathroom are manufactured - the WC and cistern, washbasin and pedestal, and bidet. Vitreous china is a white firing ceramic body with a fine texture. Once fired. A blend of clays, fillers and fluxes are vitrified during the firing process at around 1200°C and the white or coloured glaze which has been applied to the basic shape is fused both chemically and physically to the clay body. The result is a homogeneous, non-porous piece of considerable strength. The hard surface is resistant to fading, stains, burning, scratching and acid. First experiments with this recipe were made by Twyfords in 1951. Full production was achieved in December 1967 with 40 potters using the material at the Twyfords Alsager factory. Shortly afterwards vitreous china was introduced as the main product in all Twyfords factories.
Defined in British Standard BS 3402:1969 (Specification for quality of vitreous china sanitary appliances) as a strong high grade ceramic ware used for sanitary appliances.
- 20 - 30% ball clay
- 20 - 30% china clay
- 25% nepheline syenite (substitute for feldspar)
- 25% silica sand
Vitromant Brand name of Twyfords Sanitaryware. Heavy Earthenware. (See Sanitary Earthenware above) Twice fired. A white ware approximately 3/8 inches thick with a highly glazed white or coloured vitreous (non porous) surface of superb finish and attractive appearance. Twice firing to very high temperatures ensures a high standard of durability. The ideal ware for domestic use - low cost and attractive appearance make it easily the most popular ware for private houses and flats.
Vitrina Ware Brand name of Twyfords Sanitaryware. Instead of an earthenware pottery recipe. Forerunner of Duramant. Guaranteed to be non-absorbent.
Wad Clay A clay used during the process. Rope-like strip of plastic clay. Used as a cushion between saggars when they are placed together, one on top of an other in a bung, in the oven. In addition to the effect of levelling the bung, wads also seal the uneven joint between the saggars, thus preventing smoke and fumes from the the fires coming into contact with the ware during firing. Made from fireclay or saggar marl specially formulated with its own body recipe to create wad. Contains a finer grog than saggar making clay. Wad should not crack, split or fly off during firing since it could spoil the ware (particularly glost ware).
Clay recipe in the 1820s was:
- 2 Barrows full Nockings from Common Slip House
- 1 Barrow full Tough Tom
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RED CLAY Component of pottery body recipe. Etruria marl. Traditionally used for potting teapots and floor tiles.
RED STONEWARE Fine, red-coloured stoneware made to imitate Chines stoneware from Yi-hsing.
REDWARE Type of pottery with a particular recipe and requiring particular firing conditions. Can be porous in nature or highly vitrified.
REDUCING and REDUCING ATMOSPHERE The term reducing refers to how much oxygen is in the kiln's atmosphere while the kiln is firing. An oxidation atmosphere has plenty of oxygen for the fuel to burn. A reducing atmosphere occurs when the amount of available oxygen is reduced. Fire requires oxygen to burn. When there is a lack of oxygen, the fuel does not burn completely and the kiln atmosphere becomes filled with free carbon. The free carbon atoms aggressively grab any oxygen atoms they can find. In fact, carbon atoms are so oxygen-hungry that they are able to break molecular bonds. The carbon robs the clay and glaze materials of their oxygen. When the carbon reduces the amount of oxygen in the clay and glaze molecules, the colours and textures of the clay and glaze change. These changes can sometimes be quite dramatic.
REFRACTORY Ceramic material which will withstand high temperatures. A refractory material is a ceramic material (body) which retains its strength at high temperatures. Refractory products are a vital element in all high-temperature processes, such as metals making, the production of cement, glass and ceramics, and petrochemical processes. Without refractories there would be no cars, no planes, no trains, no gas or electricity, and we would be eating from wooden plates and living in mud-brick huts.
REGULATOR HOLE Part of a bottle oven. Found above the hob. Used to control the amount of secondary air entering the oven through the bag. Sometimes fitted with metal (cast iron) slides otherwise loose bricks are used to cover the holes and regulated the movement of air. Above the regulator holes is the spy hole which allowed viewing into the bag.
|Regulator hole with iron slider cover|
RELEASE Process in mould making. Clay end. The act of parting a case from its block or a mould from its case. To assist in the mould release soft soap solution is used as the release agent (or size). This release agent performs a similar job to the grease in a baking tin during baking a cake.
RELIEF MOULD Special earthenware highly-porous mould used to create clay ornamental reliefs for use on Wedgwood jasper ware. See the process here> https://www.youtube.com/watch?v=1Vi5mg5iH88
REPAIR Process. Bottle Ovens were notoriously fragile - they wore out during use. They regularly needed to be put out of use and repaired.
REPAIRING Old 18th Century word for sticking up.
RESIST Material. Clay end and decorating department. Mainly used in glazing and decorating. Resist can be applied to the surface of the pot to prevent adhesion of slip or glaze. Resists may be in the form of tape or adhesive-backed paper, or liquid. Common liquid resists include 'acki', shellac, water-emulsion, hot wax, bitumen, and latex.
RETCH (Wretch) Poorly. Sickly. Or a very poor person.
RHEOLOGY The branch of physics studying or observing the deformation and flow of matter.
RIB Equipment. Clay end. Sometimes known as a 'potter's rib.' Rubber, wooden or metal tool used during throwing to assist in creating the thrown pot. Used for smoothing the outside of thrown ware.
RIDDING Process. In the bottle oven. The thorough repair and relaying of the flues, oven bottoms, and bags in a bottle oven. A major operation which puts the oven out of use for some considerable time. Needed to be done every three years or so - depending on the work that the oven had been put to. In 1920 ridding would cost around £30. (A complete rebuild of a bottle oven, excluding the hovel, was required every 20 years)
RIDGWAY Manufacturer. Brand
RIFT Belch. Rude.
(RIGOT - unknown. Any ideas anyone? Do let us know.)
RIGHT SPIES Fundamental potter's nourishment. See Wrights Pies>
RIM in Sanitaryware. Part of a toilet. Water, from the cistern, is made to flow around the WC bowl through different designs of flush rim found at the top of the WC bowl.
1) Box rim is formed from what looks like a tube with slots and holes created in its underside. Water from the cistern is guided around the rim and allowed to jet into the WC bowl through the holes and slots. In this way water is controlled to give the best flush performance.
2) Open rim looks like an inverted U-shape. Water from the cistern is guided around the rim under its own rate of flow.
3) Rimless - these WCs have no U or slotted-tube arrangement. Water floods into the WC bowl from small jets created in the ceramic. The shape of the top of bowl (sometimes a bevelled edge) prevents water from overflowing.
RIND A BITE Dialect. This is one the authorities removed from the centre of Leek, Staffordshire, England in 2013. Tragedy for the locals. Now its a "Public Realm Area" with the sub-title "Sparrow Park." (This is entirely true. You couldn't make it up!) http://leekroundabout.weebly.com/
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RING Part of a bottle oven. Name of the circle of saggars as placed. 1st, 2nd, 3rd and 4th rings in the oven.
RING Equipment. Clay or 'pitcher' rings were and are used to keep the open top of pots such as cups perfectly round or 'true'.
RING DAMPER Part of a bottle oven. Used in some updraught bottle oven designs. These dampers where positioned on the oven crown above the first and second rings of bungs of saggars. Extra to the crown damper and quarter dampers to give a little greater control of the draughts during firing.
RINGELMANN SCALE A scale for measuring the apparent density of smoke. Dark smoke is partially burned particles of fuel, the result of incomplete combustion. It can be dangerous because small particles are absorbed into the lungs. White smoke is mainly tiny water droplets, generated when vapour released during combustion condenses in cool air. Generally, dark smoke is clearly visible against a light sky but difficult to see at night or against a dark background, white smoke is visible in darkness when illuminated but will be more difficult to see against a light sky background. Smoke is commonly measured in terms of its apparent density in relation to a scale of known greyness. The scale was developed by Professor Maximilian Ringelmann of La Station d'Essais de Machines in Paris in 1888. It has a 5 levels of density inferred from a grid of black lines on a white surface which, if viewed from a distance, merge into known shades of grey. Important in the history of the Potteries bottle oven after the enactment of the Clean Air Act 1956.
RING RAG Rag wrapped around a wedding ring to protect it when handling ware. (Many thanks go to Mick Green and his Mum, for this word).
RINGER Kiln furniture. Saggar with no bottom. Used in a bottle oven. Used to add height to a standard saggar. Also used to create greater packing density within the oven. For instance in glost placing using a ringer the lower half of one pot (basin) enters into the upper half of the saggar below.
RINKERS Dialect. large glass marbles or shotties.
RIOTS Wikipedia link here > The Pottery Riots of 1842
RISE Vertical height (in feet and inches) from the shoulder to the top of the crown of the firing chamber.
RIVETTING Old method of repairing cracks or breaks in pottery. Riveting has its origins in China. The technique was developed and used primarily on porcelain because there were no lasting adhesives available to bond such vitreous material until the formulation of epoxies and polyester resins. The process using metal clamps is destructive and unsightly. Holes were drilled either side of the break, and the rivet, usually brass or iron, was cut and then pulled into place. Unfortunately rivets often corrode and stain. Over time these antiquated repairs may become unstable and require re-restoration.
ROBEY OVEN Type of bottle oven. Downdraught. Patented, amongst others, by C Robey in 1873.
ROCKINGHAM A coarse earthenware body made from red-burning clay. The Rockingham Pottery was a 19th-century manufacturer of porcelain and earthenware. Fine wares and ornamental pieces as well as manufacturing items for ordinary everyday use.
ROLL (ROWL or RAWL) Used by a placer. A rolled up roll of fabric (or more usually ladies stockings) to form a doughnut shape, then tucked inside his hat to steady and help balance a saggar on his head. Also known as a donut and sometimes called a bun.
ROLLS Part of a bottle oven. The decorative brickwork found at the top of the neck or stack of the oven. Formed by the use of bull nosed or pig nosed bricks. A typical feature used by kiln builders to create a decoration to the oven structure.
ROLLERHEAD Equipment. Clay end. Machine for making flatware (plates, saucers and bowls.) A step change development of the traditional jigger or jolley. Ware is shaped by a revolving heated 'profile' which pushes the bat of clay down onto the surface of the plaster of Paris mould, below. The profile creates the back of the piece and the mould creates the front. The heated profile helps lubricate the process.
ROLLERHEAD JOLLEY Equipment. Clay end. Specifically for making small holloware items. (See above)
|Roller printer. Wedgwood 1970|
RONK Dialect. 'orrible, awful, smelly and vile.
RONK In a bad temper. Or a bad person. Naughty.
ROSSO ANTICO Wedgwood's name for dry-bodied red stoneware.
ROTALEC Trade name by Gibbons kilns. Type of decorating kiln. Rotary, and fast fire.
|Gibbons Rotalec Electric kiln. 1920|
ROUGE FLAMBE Decorative technique mastered by the Royal Doulton Company. See below. Deep red glaze colour created using colloidal copper in the glaze recipe and firing in a reducing atmosphere.
|Rouge Flambe. Royal Doulton Fox|
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ROULETTE Equipment. Clay end. Small hand tool used to create a pattern on the surface of a soft or leather hard clay pot, before it's fired. Consists of a small metal roulette wheel attached to handle. The roulette could be of different patterns and different widths so as to produce a variety of decorative beads. The roulette is rolled over and into the pot's surface leaving behind a band of pattern, in relief. At the Doulton, Lambeth factory in London, they called the roulette a runner.
ROULETTED WARE Pottery ware, decorated with a roulette.
|Rouletted and Sprigged jug from 1885 Spode|
ROUND The term given by casters (particularly in the sanitaryware industry) for a collection of moulds to be cast. The round contains a sufficient number of moulds for one day's casting. But no more. Many thanks to David Broadhurst for suggesting this word. March 2016
ROUND OF DAMNS A good telling off for some misdemeanour. A good cossin'.
ROYAL BLUE Colour. Decorating end. Mazarine blue, rich and deep.
ROYAL DOULTON Famous and important pottery brand and pottery manufacturer in the UK. Established in 1815 in London. Moved to Burslem in The Potteries in 1877. See Doulton>
Also visit here for more information > http://www.royaldoulton.co.uk/royal-doulton-story
RUBBER KIDNEY Equipment. Decorating department. Used to rub down lithos onto glost ware
RUBBING STONE Equipment. Tool. Used in the decorating shop. Block of fine grained abrasive sometimes fixed into a small ferule on a small stick.
RUBBING UP Process. Ovens department. Biscuit placing. Filling the spaces between individual pieces in a bung of clay flatware with placing sand to prevent warping and twisting of the pieces at the peak temperature during the firing.
RUBBER Tool. Decorating department. Used by a rubber up to rub the pattern, from a printed tissue-pull, down onto the are. See rubbing below.
|Rubbing a transfer onto the body of a teapot|
RUBBER UP Occupation. Decorating department. Usually female. Rubs the pattern from a printed tissue 'pull' onto the ware.
Q "What do you do for a living?" A "Arm a rubber up, duck".
RUBBING UP Process. Ovens department. During placing. Flatware is put together in a bung of say a dozen pieces ready for biscuit firing. The spaces between the rims of the ware are then filled with sand (if the ware is earthenware) or calcined alumina (if the ware is bone china). Handfuls of the sand or alumina are rubbed up the sides of the bung allowing the material to fill the gaps between each piece. During firing, when the flatware is prone to distort, the sand or alumina supports each piece and goes some way to prevent distortion. The process is carried out by the placer.
RUCKLED Glaze fault. Similar to crawl. The fired glaze appears patchy. Shrinkage or crawling or ruckling back of the glaze leaving exposed body after glost firing. Caused by a poor bond between the body and the glaze, usually because of dirt or grease on the biscuit body before dipping. Affected areas can vary in size from a small pinhole to several square cms.
RUMBLING Process. Ovens Department. Cleaning flint dust, sand or alumina dust from recently fired biscuit ware. Ware is placed in a revolving drum together with an abrasive material. An improvement on scouring.
RUMPTY FIZZ Dialect. Slightly naughty, slightly rude. Naughty but nice.
RUN Fault. Glaze run - glaze which has been applied too thickly so that during firing it melts and runs causing a solid drip. In studio or craft pottery runs may be created deliberately for artistic effect.
|Run - glaze fault. Over glazed|
RUN BACK Glaze fault. Similar to crawl. The fired glaze appears patchy. Shrinkage, run back or crawling back of the glaze leaving exposed body after glost firing. Caused by a poor bond between the body and the glaze, usually because of dirt or grease on the biscuit body before dipping.
RUNNER Large block of chert used in a pan mill.
RUNNER Occupation. Potting Department. Probably a youth. A mould runner, a man or a boy, ran between the maker and the drying room, carrying filled moulds for drying, and returning with empty moulds for filling. Dreadful job.
RUNNER Name of the sprigs applied to early Doulton pieces. Sprigging or sprigged decoration or ornamentation is an embossed clay decoration on pottery, usually small press-moulded clay shapes are applied to leather hard green ware.
RUNNER same as ROULETTE. Equipment. Clay end. At the Doulton, Lambeth factory in London, they called the roulette a runner. Small hand tool used to create a pattern on the surface of a soft or leather hard clay pot, before it's fired. Consists of a small metal roulette wheel attached to handle. The roulette could be of different patterns and different widths so as to produce a variety of decorative beads. The roulette is rolled over and into the pot's surface leaving behind a band of pattern, in relief.
RUNNING A BEAD Process. Clay end. A process of decoration to create a bead or band of pattern, in relief, on an unfired clay pot by using a roulette.
RUNNING OUT BUNGS When setting-in or placing a bottle oven with saggars full of ware for firing, those bungs which are nearest to the wicket were called running out bungs.
RUN OF KILN or RUN OF OVEN A trade term that died out in the mid 20th Century. More of a merchants description than a manufacturer's. It implies that the ware is unselected and goes more or less straight from the kiln into the crate or cask. Best, seconds and even thirds are packed together at one fixed price ; and usually a low one.
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