Iznik Glaze
Around the twelfth century a revolution occurred in the ceramic technique of the Islamic potters; inspired by the Chinese porcelain. Imports of that period of DING and QINBAI types showed that 'Hatay' porcelain pieces were not of similar crafting of the previous periods. The fritware was lighter finely thrown, translucent with subtle molding under a thin transparent glaze. These could not be imitated by means of the thick opaque tin glaze over a clay body in use at that time by the Ottoman craftsmen.

 
Instead the Islamic potters, led by the Persians, revived an ancient Egyptian technique, in which an artificial body material was made up from ground quartz with a small admixture of white clay and glaze. The soft paste body was then covered by thin alkaline glaze. The 'frit' body was white translucent when thin and capable of a wide range of decorative techniques. The tiles and wares had a fine white body, unequal to porcelain only in its softness, and a close-fitting brilliant glaze that allows a vibrant range of colors.
 
It is the invention of under glaze painting, however that was most significant for the history of ceramics. The under glaze painting technique required a glaze stable enough to prevent the pattern from blurring during firing; it was discovered in the use of the virtuous alkaline glaze coating (formulae unknown). For the first time the potters were able to paint freely directly on the frit body under a protective layer of glaze. The new alkaline glaze enabled the artisan to decorate the 'frit' ware with precision and delicacy. Also this
technique did not have the disadvantages of the earlier lead-glaze wares, which involved great expense in fuel and labor.
 
The most impressive products of the Iznik potters of this period was pieces crafted in the overglaze, a color or glaze applied to the existing glaze. And not, until the establishment of potteries in the west in the eighteenth century, was the range of decorative techniques surpassed (even in China).

 

Motifs and Symbols
Of all the motifs underlying the symbolism attached to objects, none recurs as frequently as that of the universe and world kingship. "God being the King of the world and 'the king' - whichever human ruler might be intended - 'the shadow of God on earth'" (Kasa'I Marvazi, 13th cent Persian poet) the world is symbolized in varied literature by the hemispherical dome to which sky, as seen by the human eye, is constantly compared. Because early bowls could be hemispherical, the sky was alternatively, referred to in literature as the 'upturned bowl' (tas-i nigun) and a rotating dome (gunbad-I gardan). These two sets of images are the key and color on pottery vessels.
 
Every metaphor used in literature for sky can be matched in pottery (and metalwork). The 'turquoise dome' or 'azure dome' is echoed many times in the crafting of lapis lazuli Iznik pieces. The lotus dome (gunbad-i nilufari) an image appears on bowls with chalice motifs on the underside. As time went by the lotus chalice gave way to an illusion of the flower or to a single lotus blossom within a rosette. (Allusions to the dome of heaven could be made in the form of an encircled geometrical pattern.)
 
During the last quarter of the sixteenth century abstract forms were added to the Iznik repertoire. They were characterized by a focal center and refracting outward, thus earning the name 'kaleidoscope' style. These designs did not reflect or resemble other Ottoman or Muslim symbolic themes. Also, functional vessels decorated in bright colors, represented an attempt to enter the lucrative foreign market, thus putting aside the ancient motifs for the demands of the trade.
 
Conclusion
During the years 1603-1717, when Sultan Ahmet was building the Blue Mosque, Iznik wall tiles and functional vessels deteriorated both in technical quality and in their aesthetic precision. This was due to conflict between the Iznik potters and court authorities: Imperial orders limited production to court needs. In the middle of the 17th century, the court removed its patronage from the Iznik potters in favour of tiles and pottery produced by the Armenian potters in Kutahya, northwestern Turkey. Armenian potters, not only crafted exquisite tiles for their churches, but also installed them in Turkish mosques from the end of the 17th century.

© Norman A. Rubin

 
Reference
 
1) "The Enchanted Forest of Iznik" Irit Ziffer Catalogue - "Birds of Paradise", Professor Nurith Kenaan Kedar - Eretz Israel Museum, Tel Aviv, Israel.
 
2) The Aesthetics of Islam, A.S. Melikan-Chirvani - Ceramics, Oliver Watson - Treasures of Islam, edited by Tony Falk, Arlines Books, Philip Wilson Publishers, England.
 
3) Lords of the Golden Horn, Noel Barber - Arrow Books, London.
 
 
Sidebar - Iznik ware
Iznik, historically Nicaea, a town centered in northwestern Turkey along the shores of Lake Iznik. It was founded in 14th century BC by the Macedonian king Antigonus I Monophtalmus. The town was an important center in the Late Roman and Byzantine times.
 
In Islamic culture, a school of Turkish pottery making that flowered throughout the sixteenth and on to the seventeenth centuries. There may have been potteries at Iznik, where there was suitable clay, as early as the twelfth century, but it was not until the late fifteenth century that Iznik pottery came into its own.