Revision of Classification and Dating of Incised Through Slip Ware (Sgraffiato) in Iran During the Islamic Period

Less historical sites can be found in Islamic lands without incised through slip wares. This type due to the variety of its designs, motifs and comparative ease of the production, has been manufactured and used in the important Islamic pottery centers specially during fourth till seventh centuries of Hijri. This is why Researchers call it as “Traditional Pottery of Islamic Lands”. Researchers confess that Throughout the Islamic territory, either based on its variety the technique and Motifs and its quantity is unique in Iran. while the classifications are ineffective and are not based on scientific information so the present research tries to reconsider the method of construction and decorating this type of pottery on the one hand and the findings of the exploration of the sites and important centers for the production of pottery in Iran in other hands, suggests some classification, and comprehensive dating of this type based on ways of making this type of pottery, Studies have been conducted on this type in Iran how it can stablish a scientific manner and the interoperability for all pottery pieces and sherds in different sites. This research has been done in this field through the collecting of information in different Libraries and comparison and identification of the findings in Archaeological sites which related to this field. The research questions include: What classification can be considered for the type of Incised through slip ware (Sgraffiato) that can cover all the samples obtained from this type of pottery throughout Iran? Or in which centuries this type produced more or for how long has it been produced in Iran? The present study was conducted through collecting information via library and field studies of findings in this field. The results of this research indicate that the classification with regard to technical and decorative properties together can be the most comprehensive classification possible, and in this regard, three general decorative styles Introduced: Incised through slip with a few sub-styles, Champlevé, and combination style. Also, unlike the opinion of most researchers whom consider time of making this pottery is limited to the 4th-7th centuries A.H, now we know that this type of pottery was produced in Iran at least until the Safavid period.
Keywords: Pottery (Ceramic), Incised Through Slip (Sgraffito), Excised-Slip (Champlevé), Splashed, Lead Glaze.
 
Introduction
Carved decoration is undoubtedly one of the most common methods of decorating pottery at all periods around the world. However, using of slip or engobe for covering dishes and pots also has a long history. This coating, in addition to the impermeability of the surface of the pottery and covering its pores and holes, has acted as an appropriate background for decorating such as painting, polishing, burnishing, and cutting the motifs.
At the same time as the period of the proto writing (the first millennium B.C.) and the entrance of the Aryan to the Iranian plateau, due to the need for mass production and acceleration in decorating, the pottery was decorated with a carved decoration instead of painted pottery. The process of using of colored slips and carving on them continued in the historical period until the introduction of the Islamic era, the Iranian pottery industry, influenced by the cultural, religious and social new atmosphere, began to flourish. Factors such as influencing and applying the experience of artists of other nations, and the most importantly the using of the scientific potential of Muslim scholars, especially chemists, led to the progressive and gradual improvement of the quality and quantity of pottery industry in Islamic era especially in the fourth to seventh centuries AH.
During this period, works and objects of pottery were produced and presented in a variety of types. This variation was particularly clear in glazed pottery, among which type of “Incised through slip ware” which was known among the archeologists of the Islamic era as “Sgraffiato”, was one of the most widespread, most used and diverse technologies. Less historic sites in the Islamic world can be found without the pieces of Incised through slip ware (Sgraffiato).
This type of pottery was built and consumed due to its considerable diversity of design, pattern, color and comparative ease of construction, in the major fields of the pottery industry throughout the Islamic world, especially during the 4^th to the 7^th A.H. Therefore, researchers call it as “Traditional Pottery of Islamic Lands” so it is considered one of the most important types of pottery in the Islamic world. Researchers confess that Throughout the Islamic territory, either based on its variety the technologies and motives and its quantity is unique in Iran. Despite the rich history of this technology, during a century that has been studied with a number of studies, it has not been dealt with in a good way, and the present classifications for it have not been based on scientific principles from the outset and even all the pieces of ceramics have been obtained. Therefore, the authors have attempted to present a typology in this area with the aim of eliminating some of the shortcomings in the classification of this type of pottery in the field.
The classification is the result of studying and reviewing of the available scientific and archaeological reports of major and main historical sites inside and outside Iran, which are in the cultural domain of Iran on the one hand, and considering the way of making and decorating in this type of pottery on the other hand. The questions raised in the current research are: What classification can be considered for the type of Incised through slip ware (Sgraffiato) that can cover all the samples obtained from this type of pottery throughout Iran? Or in which centuries this type produced more or for how long has it been produced in Iran?  Data collection was done in library and field research, and the research method based on characteristics of the subject is descriptive-analytical methods.
 
Main Part
It has to be mentioned that the most important classification belongs to Arthur Upham Pope. He proposed three groups of Aqkand or Zanjan, Amol and Champlevé or Garus to rule the studies of this species. He laid pottery in museums and art collections which had not been obtained from scientific excavations as the foundations of each of the categories in his classification, so the origin of none of them was well defined and was provided by the dealers and traders of antique presented them in the cultural property market. The objects could only be accepted in the most optimistic aspect from Iran. Another weakness and defect of this classification was the use of heterogeneous terms for sub-collections, which sometimes referred to the region (such as Aqkand or Amol or Garus) and sometimes to technology (such as Champlevé)
Therefore, relying on the style and implementation of decorative technology and in order to organize the study of the type of “ Incised through slip ware “and based on studies and related findings in different regions of Iran, we can have three general styles with sub-sections for Incised through slip ware or sgraffiato in Iran. Style 1- The Linear Incised through slip ware with four minor groups. This is the group with 4 subsets, which is the largest and most comprehensive style in Sgraffiato: The Linear Incised through slip ware with splash glaze, plain linear incised ware, linear incised ware with monochromatic coloring and linear incised ware with colorful coloring. This style is the largest and most comprehensive Stroke style. Style 2 - Excised-slip or champlevé. Style 3 – Combination of linear incised with excised through slip.
 
Conclusion
the Incised through slip wares as one of the most widespread types of pottery in the Islamic world requires general categories applicable to the major production centers. Furthermore, according to the temporal and spatial distribution of this type in Iran and its significant variation across the whole country, the classification conducted must be generalizable to all the different areas. Therefore, the Incised through slip wares of Iran are classified under three general groups of “The Linear Incised through slip”, “Excised-slip or champlevé” and “combined style” each of which has a few subgroups.
From the point of view of the chronology of this type, Famous Scholars and researchers as Fehervari, Allan, Grube, Soustiel, or Schnyder they all believe that the Incised through slip ware or sgraffiato pottery and its subgroups in the Islamic lands has been extensively produced and distributed from the late third century to the seventh century AH. and it has been stopped producing at the same time as the Mongol invasion in 7th century AH. They also believe that manufacturing this type of pottery has been replaced by other types such as Lakabi or Silhouette in next centuries.
However, recent research in some areas such as Andej or Fortress of Hasan Sabah both in Alamut area of Qazvin, based on studies of Forms of dishes and thermoluminescence dating experiments, confirmed that this type was continually produced in a large-scale by at least the eleventh century A.H. and the Safavid period, that is, several centuries after the time determined for its production. Therefore, the production of the Incised through slip ware or sgraffiato ware was not stopped at the same time as the Mongol invasion to Iran, but also continued in most of the major areas in Iran. Thus, the dating of this type of pottery in the study of the Islamic pottery needs fundamental changes and revisions.