To preserve valuable architectural works, the first step is to have a complete and comprehensive understanding of these works. Among the valuable parts of architectural works are their decorations and murals. Canvas murals are a type of mural that differs from regular and continuous murals in terms of materials, execution method, and generally in nature. Considering that the first step in preserving a work of art is its understanding and perception, the difference between these works is such that carrying out the usual methods of conservation and restoration (without a correct understanding of the work) will damage their authenticity and integrity. In the research conducted on the subject of canvas murals, some researchers place these works in the group of paintings on canvas, and some researchers also recognize these works as murals, and there is insufficient knowledge in this field. The restoration theories that have been presented and published at the national and international levels have references to the preservation and restoration of historical paintings, but they have not directly mentioned how to preserve and restore canvas murals. In order to reach the theoretical principles and foundations of the preservation and restoration of this type of murals, it is necessary to examine international charters, theories, and guidelines in the field of the preservation of historical paintings so that, according to these theories and also the studies that are carried out in the field of identifying the criteria for the preservation of canvas murals, it is possible to systematically recognize, restore, and display canvas murals correctly. In this article, the constituent layers of historical Iranian murals are first introduced, and then the results of the studies of written sources in the theoretical field of the restoration of historical paintings are presented. In fact, these studies and discussions are an introduction to the preservation and restoration of Iranian canvas murals.

Decorations and paintings are integral components of Iranian-Islamic architecture. Among the structures that continually evolve in their architectural ornaments and decorations are the mausoleums and shrines of religious figures. One such monument, adorned with diverse wall decorations, is the Imamzadeh Hamzeh ibn Musa (AS) mausoleum located in Dehneh Shirin village, Esfarayen, North Khorasan Province. This study aims to investigate the construction techniques of the wall decorations at the Imamzadeh through laboratory methods, including petrographic thin-section analysis (OPM) to identify the layers and their compositions, and Fourier Transform Infrared Spectroscopy (FTIR) to identify red and blue pigments. Petrographic analysis revealed four distinct layers in the wall paintings: the paint layer, the ground layer, the lower primer, and the upper primer. FTIR analysis could not identify the pigments, detecting only bands indicative of calcium sulfate and calcium carbonate in the studied samples. For more precise pigment identification, additional analyses such as Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX) and X-ray Diffraction (XRD) are required.
 

A part of Islamic architecture studies are architectural arrays, which are actually an integral part of the architectural work. Among the most important architectural arrays of the Islamic period in Iran are mural paintings, which can be valuable in many ways. mural paintings can connect the audience with architectural works both aesthetically and conceptually. In order to preserve the valuable works of architecture, the first step is a complete and comprehensive knowledge of these works. If a historical painting has an ambiguous identity, it must first be known for correct restoration and display so that correct interventions can be made on it and correct decisions can be made for correct display. In the present study, a painting on canvas was found from the storage of Hasht Behesht Palace in Isfahan. At first, it was thought that it was a tripod painting, but after careful examination and comparative studies, it was concluded that this work was actually a mural painting that was separated from the substrate in the previous decades using the strappo method and placed on it. It is glued on the canvas. In this article, with the description of scientific investigations on the effect and comparison of paintings on canvas and murals and conducting various scientific experiments such as chemistry, EDS and FTIR on pigments and metal sheet and metal Leaf adhesive, to a relative knowledge We achieved about painting. Further, relying on the laws of cultural heritage and the principles and theoretical foundations of restoration, a decision was made for the restoration
intervention and the correct display of the work, and the executive operation was carried out on it.

The importance of conservation and restoration of historical objects has caused the role of function, the meanings of words and their use to be surveyed in such a way as to preserve the concept of its cultural validity. This validity of words will arise in practical communication and their concepts, although appreciating will not be possible without understanding and inferring them. Also, it seems necessary to analyze the meanings and the clarity of difference and similarity of the words used for the lost areas of the painting. Objective: The aim of this research is to check the concepts of the words "lack" and "defect" in the field of conservation and restoration until their correct use is specified and also to find the appropriate word for the missing areas of paintings or lacuna. Research Method: This essay is based on a descriptive-analytical and comparative research method. It collects information from the research of predecessors, benefiting from sources related to theoretical reviews in connection with the restoration and reintegration of the lost areas of painting, and uses encyclopedias of different languages. It deals with the approaches presented by the thinkers and evaluates the special concepts of lack and defect in restoration discourse. Findings and Conclusion: In this research, it seems that lacuna in the science of Conservation and restoration means an empty space and a missing part. The word "lack" also refers to the missing part, while the "defect" part is the absence of a part from the very beginning. On the other hand, the words lacuna and lack in Latin, equivalent to Lack and Loss, indicate the missing part, although the word deficiency is equivalent to Defect. The discussion and results acknowledge that the missing areas of the painting is the same as lack, in other words, it was there from the beginning and is not present now. While the word defect represents the absent areas of the painting that were not there from the beginning and are not there now. Therefore, it seems that the word lack is a suitable equivalent for the missing part and the word lacuna..

The coffeehouse painting of the Ashura Tribulation, belonging to the Hosseinieh Kabbabi Endowment, is particularly popular among the people
of Birjand as one of the manifestations of Ashura culture. This work was commissioned based on an existing inscription by Agha Mirza Mashallah
Tehrani, who was one of the pioneers of coffeehouse painting in Iran, and was created by one of his students, Mohammad Hossein, in 1338
(A.H.), probably in Yazd. This article presents the authors' conservation and restoration experiences on the coffeehouse painting of the Ashura
Tribulation, which dates back to the late Qajar period and is exhibited in one of the old Hosseiniehs of Birjand in the first decade of Muharram.
The first step in the conservation and restoration of this work was the accurate identification of the damages, the most important of which in
this particular work is related to the damages caused by wear and tear and repeated installation of the work. After identifying the damage to
the work, appropriate conservation and restoration measures were taken, the first step being its cleaning, which was carried out in two stages. In the first stage, dust was removed. A vacuum cleaner with a soft brush and a thin mesh was used to remove dust to prevent damage to the work during sweeping. In the second stage, stains were cleaned. Inappropriate restorations were then removed, and after repairing the tears and defects, the work was strengthened to make it more stable. Conservation operations for the work included protection during display and the construction of a storage container and packaging of the work. By carrying out conservation and restoration measures, the coffeehouse painting of the Ashura tragedy of the Husseiniyeh Kabbabi was protected from further damage and its visual quality was significantly increased. This painting is kept in a designed container and will be exhibited in the first decade of Muharram at the Husseiniyeh Kabbabi location.

Many projects in the field of Protection, conservation and finally restoration of historical monuments are carried out in the country every year, However, there is unfortunately no suitable platform for sharing the practical experiences in this field within the country, which could significantly enhance the quality of these protection and restoration efforts nationwide. Emergency reinforcement of architectural ornaments is often necessary during the restoration of historical buildings. For this purpose, the restorer of architectural ornaments must create safe conditions to preserve the existing ornaments during the restoration of the building. Eram House in Yazd is one of the Qajar-era buildings in Yazd city that is currently about to be restored and repurposed. This
building, in the Central Room, features plasterwork, mirror and glass ornaments, as well as wall paintings with plant motifs and inscriptions. Due to the damage in the various layers of the architectural ornaments restorers faced challenges in reinforcing the structure and restoring the deteriorated parts of the building. Structural restoration measures posed a risk of destroying these ornaments; since the cracks indicating structural movement had caused the ornaments to detach and loosen from their underlying layers, which include: support (brick), scratch coat (straw), and top-layer (fine coat), all of which require reinforcement. The entire surface of walls, except for the ceiling wall in the Eram House, has an additional layer of gypsum plaster coating, which has obscured parts of the gypsum stucco ornaments and murals. Therefore, it is necessary to identify the hidden ornaments in different parts by conducting soundings in the walls of the Central Room of Eram House.

The Karim Khani Castle is a monument from the Zand era in Shiraz. In this building, a wall painting is one of the decorations, which unfortunately was hidden under a layer of plaster during the Qajar era, so many studies have not been conducted to identify pigments from the Zand era. The aim of the study is to understand the structure of pigments in the Zand period wall paintings in the Karim Khani Castle. The question raised is what kind of materials are included in the composition of these coloring materials. For investigation, FT-IR, SEM-EDS, and RAMAN instrumental methods were used. The findings indicate that the red pigment compositions included lead oxide (syringe) and possibly iron oxide (late), the blue pigment included ultramarine blue (lapis lazuli), and the green pigment included malachite (mountain green), which were applied on gypsum substrates and an oil-based compound was used as a binder. The pigments have a mineral structure and are durable, and despite the  introduction of European oil paints in Iran, these color compounds have not been used in mural painting.