126 North 15th Street Sebring, Ohio 44672 330-938-6920 |
In early American pottery of the 17th and 18th century, crude items were turned out by a local potter, using native clays and crude glazes. Many tried to emulate the skills of the English, and many used back stamps that directly copied and gave the impression that a piece had indeed come from Staffordshire. Even English materials were used, including English China and Ball Clays which were shipped over to Atlantic ports. The first potteries were in the mid 1600's and in the New York and New Jersey areas. Legend tells that James Bennett came to America from England in 1834 and worked in a New Jersey pottery packing house. After heading west to Indiana, he met a man from East Liverpool, Ohio and moved there to use the yellow ware clay he sought to produce. The first kiln operated in 1840 with business partners Anthony Kearns and Benjamin Harker. The first kiln produced mugs, from which they made $250. Part were sold down river and part sold by wagon. After each load came out of the kiln, operations were suspended until the ware was sold. In 1841, he sent for his three brothers to come over, and set up shop in the south side of Pittsburgh, making the first Rockingham in the US. He left the area a few years later, but Harker, Knowles and Laughlin developed white ware in the area. The Harker Pottery Plant was abandoned when they had the opportunity of securing the plant in Chester that was vacated by E.M. Knowles China Company, which in turn relocated in Newell. Homer Laughlin is credited with using the first truly American back stamp, an eagle with a British lion on its back. |
In the 1900's, ceramists as we know them today were not being educated at universities. Instead they were required to work a certain period in every branch of the business and came out well rounded. The industry made huge strides in this century, with great demand and lower costs driving the market. Development and use of raw materials became a fine art in itself, with the advent of the ceramic chemist. |
Clay Carloads of grayish blue material was shipped in by train carloads. Imported English clay was combined with other chemical elements to form the body of the semi-vitreous dinnerware. It was mined in Devonshire, Wareham and Teigngrace, England at a depth of sixty to eighty feet below the surface. It was largely an aluminum-silicate composition, and in preparation, water, flint, spar, lime, magnesium and traces of other chemical are added. The loads of clay were dumped from the train cars into large outdoor bins. It was left in the rain and sunshine elements which acted as a purifying agent. Workmen then loaded the material into wheelbarrows, weighed it, and cast it into huge mixers to be pulverized in the slip-house. In the slip house a thin paste called slip is made by adding water. The material next left the slip-house in the form of very liquid mud. The water is extracted, and press cakes are formed. It is thinly passed over a magnet which removes the tiny particles of iron, a source of grief to a potter. Iron liquefies in the kiln, expands, and makes a colored spot where it isn't desired. The monopoly in supplying clays to the USA eventually came to an end. Whiteness had always been regarded as a mark of the virtue of any dinnerware and was best obtained through using English China and Ball Clay, which were inclined to burn to a near shade of white. Ball Clay is a term used for many clays. Ball clay is actually blue. It is usually light in color and highly plastic. Unfortunately by itself, it is too slippery and fine for use unless it is combined with sand, grog or coarser less plastic clays. |
The English potters tried bringing out a cream or ivory body as something new. Imported to this country, it caught on well. The reaction of the American Potter was immediate. Unfortunately for them, the US had much stronger clays than the English, but didn't use them because of their inclination to burn to an ivory tone rather than pure white. This clay came from Kentucky and Tennessee, and most all USA manufacturers turned to exclusive use of the kaolin available in North Carolina, Georgia and Florida. Methods were developed to remove mica and other impurities. The kaolin that had been discovered before the American Revolution in North Carolina was superior to what was currently available at that time. |
Pug Mill After the Civil War, potteries were described as One Horse potteries. A business would have an old horse who ran a tread-mill to operate the slip-house where the clay was prepared for use. Before the invention of mechanical kneading of clay in a pug mill, a hefty guy wedged the clay to get it into the proper working condition by cutting it into sections with a piece of wire and socking it down on a stone slab and repeating the operation over and over. Air bubbles were squeezed out. After mixing the batch and once more adding water, the clay is made pliable for the worker, and is ready to be worked into shapes. |
Most of all hollow ware also was the product of pressers, a man who batted out he clay into a flat cake then pressed it into each half of the mold by hand. When the halves were put together and tightened by a leather strap, he would take a jolly stick and reached in and smoothed the splice. This man would have served an apprenticeship to reach this skilled level. He would begin at a discount work rate where often at the end of a day's work he wouldn't have a single piece of good ware. Handles were pressed in a separate mold and then stuck on after being trimmed and cut to fit the body of the article. Cup handles were made in the same manner until a casting slip was developed in the 1900's. |
Glaze The complicated process of glaze preparations simplified over the passing years. In the 1900's, a pottery had to have special fritt kilns, which were fired with coal, in which certain of the glaze components that were soluble in water were rendered insoluble by smelting them along with flint, feldspar, etc. Enough would be made to last several months at a time. Glazes that were made to be opaque and which were not to be stained or used over under glaze colors contained a portion of tin. Eventually, companies specialized in creating fritt, and it arrived at the pottery ready to use in bags. A Glost Kiln was used for firing glazed pieces, decal-decorated pieces, the firing is not as hot as the bisque firing nor as long. |
Dipping Room Originally, pottery was dipped into glaze in a dipping tub. The dipper deftly swished a piece of ware and then deposited it on the drip board and later it was put directly onto the mangle. A mangle was a system of moving wire trays that proceeded through heated air to emerge at the other end in a few minutes dry enough to handle. The bottom 'foot' would be sponged relatively free of glaze. It was then placed again into the saggers for a second or glost firing. Pins are placed between each piece to keep them from sticking. It left a small mark where the triangular pin touched the item, and is not to be construed as a defect. |
With new methods, glazes are applied to pottery on a belt. The operation takes them through a spray of glaze where often a heavier coating is applied to the face than to the back of the piece. |
Saggers Unfired dried green ware was placed in fire resisting receptacles known as saggers. A Sagger is a clay pot or bucket in which pieces of pottery are placed while inside a kiln to protect them from the direct effect of flames. Up to the 1920's, most every plant made its own saggers. It was a difficult occupation and was manned by hardy souls. Special sagger clay had to be provided and they had to manually put it into a soaking pit. After the addition of the proper amount of water it was aged or soaked for a few days. Clay was put in layers with grog. The grog was created from broken saggers and clay that has been fired and then ground into granules of more or less fineness. It is considered a filler and added to clay bodies for several reasons, it helps open a tight or dense body and promotes even drying, which reduces warping and cracking, and reduces overall shrinkage. These shards had to be ground by shoveling them into a chaser mill where specially hardened steel rollers crushed them against a slotted steel grid that allowed the grog to fall out. This grog performed about the same function of gravel in a cement mix, giving strength to bear weight when stacked in tiers of 20 or more in the bee hive type kilns. These fire clay baskets were filled with ware and sealed to prevent fumes and smoke from coming into contact with the ware. They were stacked on top of each other into an immense domed shaped kiln. |
There was very little change in the construction of kilns before 1900. There were difficulties in keeping the heat even throughout the kiln with the center reaching greater heat than the edges. Glazing such ware could be very difficult, as the heat changed the structure of the pieces to reduce porosity. On the outside perimeter of the kiln were placed large items such as meat platters and other articles likely to warp by too much heat, and cups and saucers were placed in the center. Ware near the door would likely be not fully fired as it was nearly impossible to close it off completely. |
Moulds Slip plaster molds are filled with slip which reduces the water content in a slip to that of most plastic clays, around 30% of total weight. The plaster absorbs water from clay. The excess slip is drained off and the cast can be removed from the mould soon after. Spaulding China had 50 casters working at the same time. Each one worked with 50-100 moulds. At any given time, the shop could be working with as many as 4,000 moulds at one time. The mould department made both new moulds and replaced used ones. Each mould could be refilled about 100 times, when it would be worn out and destroyed. Moulds were made out of plaster of paris. |
Demise of Pottery Business Louis Porter in 1927 convinced O.H. Sebring that combining several potteries together would be a way to get them on Wall Street. Offers of $20,000 per year salary were made to many of the heads and 'Crown Princes' of the industry. Joining the group was E. H. Sebring, Knowles, Taylor and Knowles, West End Pottery, Smith -Phillips, and the National China Company, Pope Gosser, Crooksville China, Coxon-Beleek and Carrollton Pottery Company signed up. While C.L. Sebring, Frank's son was ready to join, Frank H.(Tode) talked his father out of it, keeping Salem, Limoges and Sebring Pottery and Leigh Potters out of the group. The group was called the American Chinaware. It might have done well, but for the crash of the stock market in 1929. However, they also created their own problems. Sales were lost when patterns were discontinued in an effort at consolidation. Working capital became scarce, and supervisors had to be cut. Many of the plants shut down. While there was a booming need for pottery during WWII to be made in the U.S., at the end of the war things changed quickly. Tastes and attitudes of people began to change. Labor difficulties began in all industries. There were also changes in the practices of businesses. Orders were cancelled without notice, and suppliers were stuck with stock. The major competition for the Japanese market was the final blow to many industries, and pottery was hit hard. Wage rates in Sebring were the highest in the pottery industry in the United States. Pottery unions began calling for tariffs and import quotas in the 1950's but their alarms went unheeded in Washington. When Sebring's Royal China closed, it left the Homer Laughlin China Co in Newell, WV the only one left in the US making vitrified china, traditional home dinnerware. |
Airbrushing Late in the 1900's, the air brush came into pottery. Technique used small spray guns about the size of a pencil with a little container of paint. No brushes were involved. Air supply controlled the application of paint through an adjustable nozzle by a decorator. Primarily, decorating was a woman's job. They would sit at a table and each have a primary task, painting on the eyes or shading faces. Early on it was mainly used to apply a tinted edge to dinnerware, usually an under glaze of cobalt blue. Labor cost was about a penny per dozen. |
Even when very little else is left of a society, its pottery remains, enduring thousands of years of nature. Somewhere along the way, ancient man noticed that clay held water, and began using it as a vessel. Eventually he left some in the fire, and it hardened. From this beginning, he became the first potter. Around this ability, entire trade and art skills developed. Trade secrets were passed down from father to son, and potters obtained higher social status. |
The History of Pottery |
Types of Pottery Semi-vitreous ware does not attempt competition with imported vitreous. 80% of the ware gracing American tables in the 1950's were this type, also known as porcelain or semi-porcelain. Semi-porcelain is more durable, withstanding chipping, crazing and temperature change tests. Porcelain is translucent pottery with a body which is non-porous, non-absorbent, or vitrified. To be true porcelain, a piece should show the shadow of your hand when held before light. When a piece of porcelain is gently struck, there should be a clear, bell-like tone. Vitreous China is as a rule translucent. It is less durable and chips easily. |
Shaping/Pressing A trolley car moved the pliable clay to a jigger line, a series of potter's wheels. Jiggering is a process for making plates and other fairly flat items. A pancake of clay is slapped over a plaster of paris mould shaped to the form of the desired plate that represents the top of the piece, pressed down and spun. A template representing the outline of the underside of the piece is placed against the clay and finishes the shaping. The potter used water with his hands to shape the clay on a wheel. The wheel and the mould that is affixed to the bottom of the piece shape it, and a steel blade cuts off the excess. Jiggering machines were created to speed up this process. That mould is then placed on a moving rack that takes it to a heated drying room until it is dry enough to handle. This is what is known as green ware. |
Green ware During the drying process, the green ware shrinks about ten percent and loosens from the mould. It goes to the finisher, who sponges the ware and remove the rough edges. Fettling is the removal or trimming away of excess clay, unwanted blemishes, seams and flash from nearly dry pots prior to glazing and firing. It went to the green room, where it dried further. Workers moved it around the plant on a four foot board placed on their heads, and piled on top of each other. The ware could not be handled mechanically. |
Kilns A kiln is an insulated box, which is heated to fire pottery in. They can be either, cross draft, down draft, or up draft. The draft refers to the direction the combustion gas has to travel from input to exit flues. Since no combustion takes place in an electric kiln there are no input or exit flues and they are genuinely heated boxes. The fuels used to heat a kiln are gas, oil, wood, coal (now almost obsolete) and electricity. Each fuel source used to fire a kiln offers different possible outcomes for the pottery fired in them. The maximum operating temperature for most pottery kilns is about 2372 F. Kilns were constructed of several thicknesses of fire brick, reinforced by heavy steel bands, and the floor was twenty feet in diameter and was 18 feet tall. The door of the kiln was then sealed with bricks and reinforced with two steel bands. Heat in kilns was slowly introduced from underneath. |
Bisque After firing, the bisque room takes over. It is brushed, stamped with a trade mark, dressed and prepared for further processing in the dipping room. After the invention of tunnel kilns, the need for Bisque saggers was removed. Instead the ware was set on shelves made of carborundum. |
White Ware Dressing Room If the pins did not fall off the piece, employees removed them with a file in the dressing room. Pieces were also graded for quality at this time. They were sorted into firsts and seconds, and then the first were divided into selects and firsts. The seconds were also graded into seconds and thirds, making four grades, Select, first, second and thirds. The white ware is stored until time for decorating. At American Limoges, this stock room alone, at any time could contain 5 million dishes. |
Decorating and Lining In the early days of pottery, pieces were hand painted. It was both expensive and tedious. The English method was to use a system of engraving the design on a copper plate about 14 x 14". The printer who worked at a coal fired stove placed the plate on the top and deposited a gob of color which he worked into the engravings by the use of a 'spud'. He then took a long pliable spatula with which he cleaned the surface and then as a final gesture took the heel of his palm and gave it the final touches. Then he took a brush and sized a sheet of thin tissue the same size as the plate using a soft soap solution, This he laid over the plate and then ran it through a roller-press much as you may have seen done in the printing of engraved calling cards, etc. The heated plate had softened the color preparation and now dried the printing paper onto which the color design had been transferred. A cutter, a transferer and a couple of 'rubbers' made up a crew, working on a piece work basis. The cheaper patterns comprised only this treatment and were known as 'plain prints'. For more elaborate effects, these plain prints which had mostly been designed with open flowers, etc., now went to the 'fillers-in'. If it was to be a four color job, there were four girls each one supplying her particular color. Festooned edges were much in order then and it would go to the 'gilder' who would not only put on the edge line with a camel's hair brush, but would delicately hand trace much of the so-called rococo work. Gold was then in use but a bit earlier, most of the lining and hand embellishment was done in a copper luster preparation. |
Firing Kiln Overglaze - when decorations are applied to the pottery after the glost-firing, they are known as overglaze decorations. The colors are apt to be brighter and sharper. You can identify overglaze decorations by running your finger over the pottery from the background to the decorations. If you feel a change in texture, it is an overglaze. The decorating kiln bakes the pottery at more than 1,500 degrees Fahrenheit. The heat causes the aniline oils and color bands of the decoration to fuse with the piece and becoming indestructible, an advantage over hand painted pieces. In the 1900's, the old English type of double decorating muffle-kiln was used, mostly fired with coal. East Liverpool, on account of its proximity to West Virgina used natural gas firing long before other plants used it. Potteries then considered where they would move to based on the price of coal shipments. In order to help get the Sebring's to locate where they did, the PA Railroad gave them the same rate by warping the rate boundary by several miles and taking title to the ground needed for sidings for the industries. Modern potteries load items into fire retardant cars that revolve on a steel track for more efficiency. This process was invented by the Ohio State University and Harrop Ceramic Company. It took a car about 24 hours to make a complete revolution during glost firing, and 48 hours for bisque. The kilns measured from 35 to 105 feet in diameter. |
Packing and Shipping Items are carefully inspected and graded again, then sent to the packing room. Ware was packed into barrels, boxes and cartons. The English used flexible crates made of green withes. It looked flimsy, but could withstand an ocean voyage if well packed. Casks of hogsheads and barrels were standard up to the 1910's. Wooden crates were used for sets of from 31 to 66 pieces. Barrels took the 100 piece set. Each pottery usually had its own cooperage shop. These shops were on piece work and made good money. Cartons were introduced in 1912. Railroads charged a 15% penalty for using cartons until potteries worked to remove the tariff. In early times, straw was used to pack, later cardboard was used. During WWII, it was not uncommon for the boxes being used to be recycled from other uses. |
Charlie Pinkerton working the Jigger |
Moistening vats |
Compound mixing room |
Back stamping Back stamps have more of a significance now than they did at the time the pieces were created. A single company may have used many, or none at all. They could have pattern names or production dates. A new back stamp could have been created just to show off a new pattern or line. |
Migration of Potteries East Liverpool, Ohio at one time had 35 separate pottery plants. Because of space limitations, they were all multi-storied buildings. Few had a railroad siding, so that clay had to be carted long distances. Ware was also carried up and down stairs in baskets on men's heads in two story kilns. Labor was cheap and backs were strong, but it didn't make up for all the breakage. It became obvious that a level ground production was necessary. With so much land undeveloped, the potteries would have room to build and grow. That is what made the Sebring, Ohio site so attractive. |
Decalcomania & Stamping In the 1900's decalcomania began coming in from Europe. The first to use it heated the ware and then pressed the design on. Results left much to be desired. In the 1900's, gold stamping replaced hand tracing and in 1910, piece work price in Sebring was a penny per dozen for gold borders. Stamps were seldom more than a couple of inches long, so several stamps would be required. By the mid 1930's, machine stamping was used. Every company developed its own equipment. Royal China was noted for an excellent process. After the invention of decalcomania, most dinnerware, even some of the expensive kind were decorated by this transfer process. Highly skilled women completed this job. One person would apply a coat of sizing or adhesive to the ware. It then went into a drying oven. The decal was applied and rubbed well. It then passed through a mechanical washer which removed the paper backing. After drying the ware was hand painted with color lining and gold band work. Others did the gold handle work. Toilet ware was of considerable importance in the 1880-90 era. Sets could be highly decorated, going through the decorating kiln as many as five times. Tinting was done through the process known as ground-laying. An oil preparation was brushed on the ware or applied with a boss where the color was to be in evidence. Then after drying for a while, the finely powdered color was dusted on with a cotton boss. It was an unhealthy job. |
Sales Even back in the 1890's, many 'schemers' were abroad selling chinaware to general stores and others for premium purposes. Robert Johns of Chicago was one of the earliest operators and he gave many of the men who started up for themselves a good primary training. Later such folks started the Great Norther Mfg. Co., which made a killing in several lines. A chap named Kane made big selling a coupon plan to flour-millers. Newspapers were also a big factor in sales. In the 1900's, J. H. Stouffer conceived the plan of selling the idea of newspapers putting out canvassers who received a down payment of 50 cents with each order from a new subscriber who would agree to take the paper for a year and pay an added 5 cents per week. At one time he had over 25 carloads on order. This subsided when WWI began. Bloomberg began a huge plan involving newspapers in NYC, coupons and redemption sites. Others came along using the same tactics, and they spent a lot of time suing each other. Drug stores have distributed large quantities of china on various coupon and punch-card plans. People's Drug used over 150,000 32 piece sets from Salem in the 1930's. The housewife paid $2.98 for a set costing about $2.72 at the factory. Food chains used about 130 car loads of Salem dinnerware by American Stores of Philadelphia on a punch-card deal. As early as 1901, Mothers Oats and others were packing a piece of dinnerware in each package of rolled oats. The largest items were either a pie plate or bread and butter plate. |
Sam Hutmacher Royal China age 17, 1912 |
Boxing - rim to rim nestling of pottery bowls or cups to prevent warping while drying and firing. |
Cones Cones are composed of clay and glaze material, designed to melt and bend at specific temperatures. By observing them through a small peep hole in the kiln it is possible to ascertain the exact conditions in the kiln. Cones are a better indicator than temperature alone as the degree of glaze melt is a combination of time and temperature. Cones are numbered from cone 022 up to cone 42. Cone 022 is the lowest melting cone and requires the least amount of heat to deform or bend. During firing, a cone softens and melts as it is heated. Cones used on the kiln shelf bend due to the effects of gravity pulling the tip down. This bending indicates the cone and the piece of pottery has received a specific amount of heat. It typically takes 15 to 22 minutes for cones to bend fully once they start bending. Each higher cone number requires more heat to bend. A cone 01 needs less heat treatment than cone 1 and cone 020 needs less than 019. Although cones do not actually measure temperature, cone bending behavior and temperature are related. The faster the firing, the higher the temperature required to bend the cone and the slower the firing, the lower the temperature required to bend the cone. The 6 o'clock position, 90 angular degrees, is considered the end point of cone bending. |
Peep Hole - kilns have two or three sections stacked on top of each other and each section has a one inch hole that has a removable ceramic plug that can be removed to check progress of firing by looking at cones. |
Wall of the inside of a glost kiln |
The heat was increased to the correct temperature and kept there for 44 hours. It was then gradually allowed to cool. The ware removed from this first baking is called biscuit or bisque. It is now semi-vitrified, or partly glass formed, though still porous. Bisque is a greenware piece of pottery that is fired at a high temperature and is porous and unglazed. The pottery is easier to handle due to the hardness and warping from shrinkage can be controlled a little easier by setting the pieces in sand during the firing. Due to it’s porosity it is easier to get a glaze to adhere to it. The temperature range for firing is red heat 1562 F to 1832 F. In the kiln, the clay goes through the slow chemical process of clay becoming ceramic. Clay which is exposed to heat 1112 F looses its chemically bound water molecules and can no longer be broken down by water. Once this change has occurred it cannot be reversed. |
Inside the glost kiln |
Tunnel Kilns changed how pottery was made. One of the first was built for Limoges China in Sebring by Phil Dressler. It was built solid up from the floor. It needed a very long building, which wasn't always available for a pottery in a city. Thus, circular tunnel kilns were invented. While the old style of kiln required the hand to run up and down steps carrying ware both on his head and in his hands, the new kilns were all on ground level. While the long-flame, low-sulphur coal from the Pittsburgh district met the demands of potters in the E. Liverpool, Ohio for many years, fuel oil improvements brought about new kilns. At the F. A. Sebring plant a carload of tanks were purchased at Nitro, WV, from an abandoned government project. Mostly the idea was to use #6 fuel oil which was the least expensive and promised the most BTU's. Oil was purchased from men who kept office in their hat. Every now and then some one would smuggle in a carload from the Smackover field in Arkansas where the high sulphur content played havoc with the kiln contents. In zero weather the oil would be so stiff a man could walk on the surface of the oil. All cars had to have steam coils in them so they could hook up with the boiler. Same was true of storage tanks and fuel lines. Filters were continually clogged. |
Orifices on burners went wrong and streams of oil were impinged onto the brick work, to the great glee of brick layers. Burner salesmen then sold them new ideas that caused even more problems. When the plants went back to coal, the tanks were junked lest someone might be tempted to try it again. Natural gas was used for firing intermittent burners in East Liverpool years before other areas had it available. However, the gas |