HISTORY
Dinnerware pieces are among the oldest objects created and used by humans. Nearly every primitive society produced dinnerware in some form or another. In addition to their use as eating utensils and food containers, early dinnerware pieces were also used for carrying water and cooking.

The Chinese are credited with inventing what most people consider today's dinnerware, as well as the development of processes which eventually led to the mixing of clay and stone to produce the first true porcelain. Continued development and experimentation led to the discovery of fireable clear and colored glazes, as well as individualized decoration. These modern dinnerware pieces migrated to Europe via established trade routes to the West, where they became highly-prized items.
Formula and production processes used to create dinnerware in Europe were continually developed and refined, eventually yielding the fine patterns and sets known today.

Current dinnerware design owes much of its development to advances made in body and glaze formulas, decoration methods, and manufacturing techniques that occurred in England's Staffordshire pottery district between 1750 and 1850. For the most part, English designers and manufacturers set the dinnerware quality standards for the rest of the world.
Today's ceramic dinnerware is produced using a mixture of raw materials, including different types and grades of clay, stone, glass and bone ash. These materials - combined with standardized firing temperatures - produce dinnerware types of all kinds including pottery and earthenware, stoneware, porcelain, and bone china.

 

The Ceramic Production Sequence
The following are general descriptions of the available types of ceramics used at Gibson:

· PORCELAIN

  • Fine China
  • Bone China

·  STONEWARE

·  EARTHENWARE

  • Pottery


BASICALLY SPEAKING, THE PRODUCTION OF CERAMICS CONSISTS OF THREE PHYSICAL ELEMENTS:

A) BODY
B) GLAZING
C) DECORATION

I. THE BODY -- MIXING OF SAND AND CLAY

II. FORMING THE SHAPES OF EACH INDIVIDUAL ITEM

  • Hand
  • Casting
  • Stamping
  • Jiggering

 

III. USING MACHINES

  • Jiggering machine (roller) - makes mugs, dinner plates and bowls
  • Machine pressed - most efficient method to produce oversized platters. Our turkey platters, for example, are made from machine pressed
  • Casting - liquid clay is poured into a mold and then allowed to set. This process duplicates the shape of the mold. Teapots, cookie jars and any other three-dimensional products are casting items. Slower production, therefore, more costly to create.

    A. Sample Mold:

    1. Sculpting the shape with soft clay
    2. A plaster mold is made from the sculpture
    3. This process takes five to seven days
    4. Once sample mold is approved, then a "production mold" must be made

    B. Production Mold:

    1. Duplicating the plaster mold, make as many molds as necessary, depending on size of order
    2. Each mold is usually good for 60 to 80 turns before making new production molds

 

IV. PRODUCT PLACED THROUGH FIRST OVEN

  • Temperature is set at 175° F. Purpose is to remove the excess water content from the formed item and harden the formed shapes.

 

V. GLAZING PROCESS (click here to find out more about glazing)

  • Natural (Beige)
  • White
  • Colored



VI. BISQUIT KILN (SECOND OVEN)

At this stage each item is solid and hard. Temperature varies for each item:

·  1,500° F - Porcelain

·  1,500° F - Stoneware

·  1,800° F - Earthenware

VII. DECORATION APPLICATION (click here to find out more about decoration)

(One more glazing if it is underglaze production)

·  Decal

·  Handpaint (usually done before Stage V)

·  Stamped (usually done before Stage V)


VIII. GLOST KILN (THIRD OVEN)

At this point the product is fully baked and ready for packaging

·  2,350 - 2,400° F - Porcelain

·  2,250 - 2,350° F - Stoneware

·  1,800 - 1,900° F - Earthenware


IX. QUALITY CONTROL

The product should be inspected against the following during all production stages:

·  Smoothness/Finish

·  Warpage

·  Breakage

·  Chipping


X. PACKING

Depending on the complexity of the specific manufacturer, the product is inspected against:

·  Smoothness/Finish

·  Warpage

·  Breakage

·  Chipping

THE DIFFERENCE IT MAKES

PORCELAIN

Porcelain, also referred to as fine china and bone china, depending on quality, is made with fine clay and sand. Fine china is traditionally considered elegant and elite porcelain, while bone china has become a higher standard in the industry. Bone china is produced from the purest and finest quality sand and clay. A percentage of animal bone is also added to offer extra strength, as thinner cross sections are manufactured. The end result is a more well-designed and almost see-through object.

Generally speaking, porcelain is made with high quality clay and sand. Also, due to its high firing temperatures (2,350° - 2,400° F) it is much more compact. Thus, it can better accept the outer coating. Since it does not absorb much of the glaze liquid, its milky color is preserved. The end result is a white shiny surface with the thinner cross sections, creating a more beautiful and elegant appearance.

STONEWARE

With this material, the mixture of clay and sand tends to generally be more course. Therefore, some stone is added. It has a lower firing temperature (2,250° - 2,350° F), so it has a tendency to be thicker and bulkier than porcelain. The original clay body absorbs some of the liquid glaze, ending up with a beige finished color. However, more modern techniques have offset this absorption, allowing for white stoneware to be available.

Colored glaze is also being produced, and this type uses special chemistry to create the corrected final color surface, instead of a white color.

Stoneware, for the most part, is very durable, and during the firing, large air intake is allowed so most of the carbon content is burned off. Also, the glazing of stoneware does not chip as easily as most other porcelains. Stoneware's strength and durability are especially appropriate as functional ware because it stands up well to constant use and frequent cleaning.

EARTHENWARE

Pottery is the basic form of earthenware, without its outer glazing. This is the reason for the brownish color, as it retains its original clay look. Earthenware is made with a larger percentage of clay material, and a higher temperature (1,800° F) is exerted in the second oven to better solidify the initial soft clay.

Earthenware bodies are not as durable and resistant to chipping as a high-fired body ceramic. On the other hand, earthenware is much lighter in weight due to less density and can be decorated with brighter-colored glazes because of the lower firing temperature. It is very well suited for the colorful, handpainted designs unique to Gibson.

STONELITE

Combines the merits of both earthenware and stoneware - can be colored as brightly as earthenware, and maintains the density and strength of stoneware.


DINNERWARE DÉCOR

GLAZING

The glaze is a smooth and hard shell that is applied to the outer surface of the body. The components are of a variety of additives specialized by each individual country, region and factory where the product is made. The end result being:

  • Smoothness
  • Strength
  • Color
  • Shine

DECAL

Decal is a design technique similar to a paper rub-on. Tiny dot screenprints of different color designs are mechanically transferred onto a transparent surface. This layer is then lightly glued onto a paper-like base. At the time of production, the upper transparent layer is removed by water and then hand-positioned on the ceramic's body. Next, the decal layer is placed through a heated oven and baked onto the body of the ceramic, creating a solid surface.

Most decal decorations are overglazed. If a final glazing follows the decal application, it is called underglazed. This type is usually more expensive because of the extra step. If you rub your fingers on the surface of an underglazed product, you cannot feel the decal bumps typical in overglaze.

HANDPAINTED

Handpainted designs are today's most popular decorations for dinnerware. In this case, skilled workers use paintbrushes or sponges to apply a series of colors on the surface before glazing. This process is naturally more time-consuming and may be more costly, but the end result is a beautiful, unique item, different from anyone else's.

STAMPED

Stamped decoration is yet another way to create a special design on a product. A ready stamp is dipped in paint and then applied either by hand or machine to the product. Some factories have been able to skillfully utilize a combination of the above methods to better suit economic and aesthetic needs.

 

CERAMIC INDUSTRY TERMS AND DEFINITIONS

A COMPLETE GLOSSARY

Bisque (or Bisquit): clayware that has been fired once for hardening, but has not yet been glazed.

Bisque fire: the first firing, or baking, in clayware manufacture, which hardens the ware into its final shape.

Blank: an undecorated piece of dinnerware or glassware, usually one that will be subjected to further processing for decorating.

Body: the physical composition of a piece of clayware as opposed to its glaze or decoration.

Body types:

  • Clay
  • Dolomik
  • Earthenware (ironstone)
  • Stonelite
  • Stoneware
  • Porcelain/china/fine china
  • Bone china

Bone China: china that contains a varied percentage of animal bone ash, mostly ox bone, which is burned and ground to a fine powder for added strength, translucency and whiteness. Developed originally in England, but now made in many other countries as well.

Bright gold: a liquid gold paint decoration which, when fired, comes out bright and therefore requires no burnishing or polishing.

Casting: a process in which liquid clay, or slip, is poured into a mold and then allowed to set. The result is a piece of clayware duplicating the shape of the mold.

Casual china: a non-porous type of clayware made of special white clay and fired at exceptionally high temperatures. The finer grades are generally thin, translucent, resistant to chipping, and ring clearly when struck. The word should not be used as a generic term for all dinnerware.

Ceramics: a generic term referring to articles made of so-called earth materials (clay, sand, etc.) processed by firing or baking. The classification includes pottery, earthenware, porcelain, china, fine china and bone china.

Clay: The essential raw material for ceramic formed when rock breaks down either due to the weather or through chemical processes as in the clay used for dinnerware.

Coup shape: a contemporary plate shape lacking a shoulder, like an inverted Frisbee, flat across the diameter and rolled up slightly at the rim.

Crackled ware: clayware whose surface is marked by a network of tiny cracks deliberately induced for decorative effect by sudden cooling.

Crazing: a defect in clayware glaze consisting of a network of tiny cracks caused by the difference in the rate of contraction between body and glaze. It is almost the same in appearance as deliberate cracking.

Decal: a special design-bearing sheet used in dinnerware decoration. The paper is then removed resulting in the transfer of the decoration to the ware. Subsequent firing makes it permanent.

Earthenware: a type of clayware fired at comparatively low temperatures producing a heavy porous body that is opaque, not as strong as stoneware or china, and lacking that product's resonance. Earthenware dinnerware is typically in the low and medium price brackets and lends itself to a variety of decorative styles and methods, making it well-suited for everyday use. There is some high-priced English earthenware.

Embossing: a raised or molded sculpting produced either in the mold or formed separately (seldom done), and applied before firing.

Feldspar: a common mineral used in some china and glazed materials.

Filling-in: a decoration process whereby transfer print outlines applied to a piece are filled in by hand to produce multi-colored effects.

Firing: a baking process under carefully controlled temperatures to which all ceramic ware is subjected for either hardening, strengthening, or fusing.

Fine china: thin and translucent, it is quite strong in spite of its delicacy. It is made of top quality clays fired at high temperatures that cause them to fuse into a hard, non-porous body.

Flatware: in dinnerware, any flat or near-flat piece such as a plate or platter.

Glaze: a glossy transparent or colored coating baked onto a clayware body for decorative purposes and to make it non-absorbent and more resistant to wear.

Hollow ware or hollowware: any clayware pieces, such as cups, pitchers, of bowls that have three-dimensional properties, as opposed to flatware.

Hotelware: heavy china dinnerware made specifically for use in hotels, institutions, etc. It is stronger than china for home use, but has neither the transparency nor the delicacy of the latter.

Ironstone: a much misused term that should be used only in reference to earthenware of good quality and better-that-average strength. True ironstone was originally developed in England. Originally it was a form of stoneware said to contain powdered iron slag. Ironstone has a slightly porous body.

Jiggering: jigger machine used to make mugs. A rotating system is used to form the clay into the shape of the mold.

Kiln: the oven in which ceramic ware is fired or baked.

Banding (or Lining): a dinnerware decoration, either machine-or-hand applied, consisting of one or several parallel lines running around the outer edge of a plate.

Luster: a ceramic glaze coating, metallic in nature, which gives the finished piece an iridescent effect.

Matte finish: a flat glaze finish without a gloss or reflective shine.

Melamine: chemical name of the plastic compound generally considered the leading plastic for making dinnerware.

Mould: a plaster of paris mould of the clay shape from which a clay form can be reproduced.

Nappy: in dinnerware, a round vegetable dish. A glassware nappy, however, is any round or square dish from fruit size up, used for various serving purposes.

Open stock: an approach to dinnerware retailing in which the ware is sold in individual pieces or small groups rather than in complete, predetermined compositions or sets. Implied, also, is the fact that patterns offered in open stock will be available for an indefinite period following their introduction.

Ovenware: clayware that is able to withstand the heat of a kitchen oven without damage, thus permitting a homemaker to prepare oven-cooked food in it and then use it for table service.

Overglaze decoration: design applied to clayware after it has been glazed.

Place settings: usually five (although today four and even six are becoming common) matched pieces of dinnerware for setting a single place at a table. The pieces most commonly included are a dinner plate, salad plate, soup/cereal bowl, cup and saucer.

Porcelain: a hard, translucent clayware body that differs very slightly from china in ingredients and manufacturing process. In most respects the two are so much alike that the term may be used interchangeably. Porcelain usually consists of 50% kaolin, 25% quartz, and 25% feldspar. Kaolin provides plasticity, durability and consistency and influences the whiteness of the body. Quartz provides stability and feldspar provides vitrification.

Porosity: the ability of clay to absorb moisture.

Pottery: can be used as a generic term, much the same as "ceramic." When referring to a specific ware, pottery refers to a very durable form of clayware made of crude clay and fired at comparatively low temperatures. It lends itself best to colorful, informal decoration and simple shades.

Potter's wheel: a round platform rotated either mechanically or manually upon which the potter throws, or forms, a circular shape.

Reject: a piece of ware, which, because of an imperfection, does not meet certain quality standards and therefore is withheld from shipment.

Run of kiln: (or R.K. or R.K. selects): the entire production runs without quality control to separate second grades and rejects.

Salt glaze: a semi-matte or half-glossy glaze obtained by injecting salt into the kiln during the glaze firing.

Screenprinting: a method of ceramic and glassware decorating in which stencil-like screens are used in applying colors to the ware.

Second grade: ware that exhibits noticeable minor defects that do not affect the ware's usefulness.

Selects: near-perfect dinnerware pieces as indicated in a process of selection in which imperfect pieces are removed from the group.

Shoulder: the raised rim of the traditionally rim shaped plate.

Silica: one of the earth's most abundant minerals and a vital ingredient in ceramic manufacture. It is the basic component of glass as well as of ceramic glazes and high-quality clayware bodies.

Slip: a mixture of clay and water with a cream-like consistency. It is used both for producing ceramic body and for ceramic decoration.

Stonelite: somewhat improved earthenware, it combines the merits of both earthenware and stoneware. Bright as earthenware, it is dense and strong like stoneware. It stands up well to constant use.

Stoneware: a hard addition of grinded stone clayware made of light-colored clay and fired at high temperatures (2,400 degrees). It is non-porous and quite durable but does not have the translucence of fine china.

Terracotta: a brownish-orange earthenware commonly used for ceramic sculpture, ornament, and dinnerware. It is an Italian term meaning baked earth.

Texture glaze: a colored glaze in which dripping, eruption, or some other controlled disturbance is introduced to heighten the decorative effect.

Throwing: forming clay manually by shaping it as it is rotated on a potter's wheel, or revolving platform.

Translucence: that quality of fine china or melamine dinnerware that makes it semi-transparent. Placing the hand across the back of a piece and holding it up to the light may demonstrate it. A silhouette of the hand will be visible through the body of the piece.

Transfer printing: a decorating method similar to the one in which decal is used but permitting only one color at a time to be applied.

Tunnel kiln: a long tunnel-like oven in which clayware is fired by being carried through on flat cars that move along very slowly.

Unbreakable: literally, a dinnerware piece that will not break under any circumstances. Because such ware does not exist -- even glass, ceramic, or melamine dinnerware will break under certain conditions -- the phrase should never be used. The correct way to describe unusually strong dinnerware is "break-resistant."

Underglaze decoration: a ceramic decoration that is applied directly to the biscuit, or underglazed body, and then covered with a protective glaze coating that makes it highly resistant to wear and in which the decoration (decal) is not felt, creating a smooth surface.

Vitrified: stoneware and porcelain fired at higher temperatures, creating a stronger bond between the bisquit and outer glaze creating a more durable and harder object.