Differences Between Porcelain and Iznik Ceramics
Turkiye enjoys worldwide reputation in the field of tiles and ceramics. The centuries-old tile and ceramic history of our country is now a living craft and an important sector thanks to industrial production. However, porcelain and Iznik tiles have been confused with each other for years, and at times misinformation has spread that Iznik tiles are porcelain or faience. Let’s take a look at the differences between these two ceramics, which, although thought to be very similar, are not really similar in terms of their structure and field of application.
Let’s start by first understanding what ceramics are. Ceramics is the name given to pots and pans made of “plastic clay”, that is, earthenware that has the ability to form by sticking together when the clay in nature is thinned. The word keramos, which in Greek means “clay, clayey earth, potter’s earth and earthenware”, was translated into various European languages as “keramik” or “ceramics”.
It is the clay that enables the formation of ceramics. When clay is mixed with water, it is kneadable enough to be molded. It is formed by the crumbling of aged rocks, usually with silica, iron oxide, limestone, and mica mixtures that occur naturally, over millions of years by the actions of water, wind, etc.
Although porcelain is classified as a type of ceramic, porcelain and ceramic have very different properties. The raw material of porcelain consists of clayey earth, quartz and feldspar minerals and is baked at a higher temperature than ceramics (in the range of 1200-1500 degrees Celsius). They differ from each other in terms of manufacturing techniques and raw materials. Ceramic is a matte material, opaque, but less resistant to water. Porcelain, on the other hand, is used primarily for items such as cups and teapots that are in constant contact with water and must be transparent. Porcelain is less durable than ceramic, which is why ceramic is preferred for various wall coverings. Ceramic has a rougher texture than porcelain. Therefore, porcelain is used when a smooth texture is desired and ceramic is used when a rough and non-slip texture is desired. Porcelain is more resistant to sudden temperature changes than ceramic. For example, a high quality porcelain teapot will not be damaged by heat.
Iznik tile, on the other hand, contains a high proportion of quartz, glass powder and clay. Quartz, a semi-precious stone, is the most important raw material for tile production. Although it is a ceramic that has a porcelain effect, its manufacturing process and range of uses are very different from porcelain. When porcelain is to be decorated, the technique of on-glaze decoration is used, i.e. the decoration is applied after baking. Iznik tiles, on the other hand, undergo underglaze decoration. The colors used are obtained from metal oxides; this is one of the reasons why the tiles remain intact for years. The tiles get their vivid, protected, deep and striking beauty from the glaze (glass). Unlike porcelain, the baking temperature of Iznik tiles, which are baked twice, is about 950 degrees. Iznik tiles are also called stone tiles. The reason for this is the presence of quartz in four main layers, and the high proportion of quartz gives the tile its durability. The layers are the base body, the primer, the colors and the glaze. In addition, these layers must harmonize with each other during baking. Otherwise, the products may come out of the kiln with cracks or the glaze layers may fall off after a while. Porcelain was mainly used for dinner services, vases and decorative items. Iznik tiles, on the other hand, were primarily used as wall ornaments and were also produced as decorative items in the following years.
We have put together the most important differences so that you do not confuse this Turkish ceramic, the Iznik tile which is exhibited in world-famous museums and is of great interest to art lovers, with a completely different type of ceramic such as porcelain. You can find more information about Iznik tiles in our other blog posts (‘Beauty from Fire: Tiles and Ceramics’, Delphin Hotel Blog Post, ‘What are the differences between ceramics and porcelain?’, Yurtbay Seramik Blog Post, Turkish Art ‘Ceramics’, Kültür A.Ş., pp.1-2).