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
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
The Ceramic Production Sequence
The following are general
descriptions of the available types of ceramics used at Gibson:
BASICALLY SPEAKING, THE PRODUCTION OF CERAMICS CONSISTS OF THREE PHYSICAL
I. THE BODY -- MIXING OF SAND AND CLAY
II. FORMING THE SHAPES OF EACH INDIVIDUAL ITEM
III. USING MACHINES
- Jiggering machine (roller) - makes mugs, dinner plates
- Machine pressed - most efficient method to produce
oversized platters. Our turkey platters, for example, are made from
- 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
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
B. Production Mold:
the plaster mold, make as many molds as necessary, depending on size of
2. Each mold is usually good for 60 to 80 turns before making new
IV. PRODUCT PLACED THROUGH FIRST
- 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
- Natural (Beige)
VI. BISQUIT KILN (SECOND OVEN)
At this stage each item is solid and
hard. Temperature varies for each item:
F - Porcelain
F - Stoneware
F - Earthenware
VII. DECORATION APPLICATION (click here to find out more about
(One more glazing if it is
(usually done before Stage V)
(usually done before Stage V)
VIII. GLOST KILN (THIRD OVEN)
At this point the product is fully
baked and ready for packaging
- 2,400° F - Porcelain
- 2,350° F - Stoneware
- 1,900° F - Earthenware
IX. QUALITY CONTROL
The product should be inspected
against the following during all production stages:
Depending on the complexity of the
specific manufacturer, the product is inspected against:
THE DIFFERENCE IT MAKES
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.
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.
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.
Combines the merits of both
earthenware and stoneware - can be colored as brightly as earthenware, and
maintains the density and strength of stoneware.
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:
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 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 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
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.
- Earthenware (ironstone)
- 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
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
Glaze: a glossy transparent or colored coating baked onto a clayware
body for decorative purposes and to make it non-absorbent and more resistant
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
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
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
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
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
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.