I have often wondered if people really know what they are buying. When they see a price and say it is expensive, then we say "But this is porcelain", do they really know what that means?
I have decided to compile a series of posts of information on materials connected to brands we have in order to make my readers aware of what we have at Koti. Most of the information I will have taken from other places so that we may have them all in one place. (See references below.)
To start off with, here is a list of porcelain types and names associated with porcelain: pottery, fine china, bone china, soft-paste porcelain, and hard-paste porcelain. I won't be talking about all of them since porcelain can be divided into only 3 main categories: bone china, hard-paste porcelain, and soft-paste porcelain
All porcelain is defined as coming from pottery. Kaolin clay is the main component in porcelain. Raw materials added to the kaolin clay make it porcelain and depending on the raw material you can change the type. Raw materials can include feldspar, ball clay, glass, bone ash, steatite, quartz, petuntse and alabaster.
Properties associated with porcelain include low permeability and elasticity; considerable strength, hardness, toughness, whiteness, translucency and resonance; and a high resistance to chemical attack and thermal shock.
: Hard-paste Porcelain originated in China around the 9th century. These exported Chinese porcelains were held in such great esteem in Europe that in the English language china became a commonly–used synonym for the Franco-Italian term porcelain. Its components are feldspathic rock petuntse and kaolin fired at very high temperatures (1400°C) with it being almost impermeable to water.
: Soft-paste Porcelain can be described as bone china, Seger porcelain, vitreous porcelain, new Sèvres porcelain, Parian porcelain and soft feldspathic porcelain. Soft-paste porcelain tried to replicate Chinese porcelain in the 1500s. Characteristics include being difficult to mold, being more granular and needing to be fired at low temperatures (1200°C) in respect to hard-paste porcelain.
Vitreous porcelain refers to the type of enamel used to decorate the surface. Here is a brief description:
Ceramic material that has been glazed with enamel is often referred to as "vitreous china." When an intense amount of heat is applied to powdered glass, the result is a liquid glass that is used to coat small objects. When this glass is allowed to cool, china manufacturers are able to create vitreous china. Frequently, this type of china takes on a gold hue, though other colors are also possible.
The practice of coating an object with enamel has been in existence since the Ancient Egyptians. Following the Egyptians, the Ancient Greeks, Chinese, Russians, and Celts adopted the craft of creating vitreous china. In addition to coating ceramic objects with enamel, these ancient civilizations also applied fused powdered glass to metal objects.
Historically, creating glass powder was possible through the crushing of glass, or through mixing colorless glass with metallic oxide. Various designs were then hand-painted over the top of the cooled glass. Following the painting of an object, all items had to be fired inside of a large wooden oven that was capable of heating these objects to very high temperatures.
: Bone China is a translucent porcelain made with bone ash. A man by the name of Thomas Frye invented the bone china process but it was Josiah Spode who perfected this process in Spoke-on Trent, England in the early 1800s. Bone china has a consistency of at least 25% cattle bone ash and is known not only for its translucency but also for its very high levels of whiteness and very high mechanical strength and chip resistance.
Traditionally English bone china was made from two parts of bone-ash, one part of kaolin clay and one part china stone (a feldspathic rock), although this has largely been replaced by feldspars from non-UK sources.
(To check quickly if you have bone china just hold your dish up to a light source. If you can see your hand through it then you have bone china.)
Here is a video on how the US brand, Lenox, makes their porcelain in modern days.
References
http://en.wikipedia.org/wiki/Porcelain
http://en.wikipedia.org/wiki/Pottery
http://home.howstuffworks.com/lenox.htm
http://www.thepotteries.org/potters/spode.htm
http://en.wikipedia.org/wiki/Soft-paste_porcelain
http://www.wisegeek.com/what-is-vitreous-china.htm
http://en.wikipedia.org/wiki/Hard-paste_porcelain
I have decided to compile a series of posts of information on materials connected to brands we have in order to make my readers aware of what we have at Koti. Most of the information I will have taken from other places so that we may have them all in one place. (See references below.)
To start off with, here is a list of porcelain types and names associated with porcelain: pottery, fine china, bone china, soft-paste porcelain, and hard-paste porcelain. I won't be talking about all of them since porcelain can be divided into only 3 main categories: bone china, hard-paste porcelain, and soft-paste porcelain
All porcelain is defined as coming from pottery. Kaolin clay is the main component in porcelain. Raw materials added to the kaolin clay make it porcelain and depending on the raw material you can change the type. Raw materials can include feldspar, ball clay, glass, bone ash, steatite, quartz, petuntse and alabaster.
Properties associated with porcelain include low permeability and elasticity; considerable strength, hardness, toughness, whiteness, translucency and resonance; and a high resistance to chemical attack and thermal shock.
: Hard-paste Porcelain originated in China around the 9th century. These exported Chinese porcelains were held in such great esteem in Europe that in the English language china became a commonly–used synonym for the Franco-Italian term porcelain. Its components are feldspathic rock petuntse and kaolin fired at very high temperatures (1400°C) with it being almost impermeable to water.
: Soft-paste Porcelain can be described as bone china, Seger porcelain, vitreous porcelain, new Sèvres porcelain, Parian porcelain and soft feldspathic porcelain. Soft-paste porcelain tried to replicate Chinese porcelain in the 1500s. Characteristics include being difficult to mold, being more granular and needing to be fired at low temperatures (1200°C) in respect to hard-paste porcelain.
Vitreous porcelain refers to the type of enamel used to decorate the surface. Here is a brief description:
Ceramic material that has been glazed with enamel is often referred to as "vitreous china." When an intense amount of heat is applied to powdered glass, the result is a liquid glass that is used to coat small objects. When this glass is allowed to cool, china manufacturers are able to create vitreous china. Frequently, this type of china takes on a gold hue, though other colors are also possible.
The practice of coating an object with enamel has been in existence since the Ancient Egyptians. Following the Egyptians, the Ancient Greeks, Chinese, Russians, and Celts adopted the craft of creating vitreous china. In addition to coating ceramic objects with enamel, these ancient civilizations also applied fused powdered glass to metal objects.
Historically, creating glass powder was possible through the crushing of glass, or through mixing colorless glass with metallic oxide. Various designs were then hand-painted over the top of the cooled glass. Following the painting of an object, all items had to be fired inside of a large wooden oven that was capable of heating these objects to very high temperatures.
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| Siirtolapuutarha Bowls and Cups Vitreous porcelain from Marimekko |
: Bone China is a translucent porcelain made with bone ash. A man by the name of Thomas Frye invented the bone china process but it was Josiah Spode who perfected this process in Spoke-on Trent, England in the early 1800s. Bone china has a consistency of at least 25% cattle bone ash and is known not only for its translucency but also for its very high levels of whiteness and very high mechanical strength and chip resistance.
Traditionally English bone china was made from two parts of bone-ash, one part of kaolin clay and one part china stone (a feldspathic rock), although this has largely been replaced by feldspars from non-UK sources.
(To check quickly if you have bone china just hold your dish up to a light source. If you can see your hand through it then you have bone china.)
 |
| Spoke-on Trent Bone China from Donna Wilson (coming soon to Koti!) |
References
http://en.wikipedia.org/wiki/Porcelain
http://en.wikipedia.org/wiki/Pottery
http://home.howstuffworks.com/lenox.htm
http://www.thepotteries.org/potters/spode.htm
http://en.wikipedia.org/wiki/Soft-paste_porcelain
http://www.wisegeek.com/what-is-vitreous-china.htm
http://en.wikipedia.org/wiki/Hard-paste_porcelain
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