Micromosaics
Artist: Unknown
Date: Late 18th-early 19th century
Classification: Micromosaics
Dimensions: Various
Materials: Gold and micromosaics; silver and vitreous paste
Adopted By: The Texas Chapter
Description
MEDIUM PRIORITY PROJECT
The Vatican Museums’ collection of micromosaics (also known as miniature mosaics) represents one of the most important collections in the world. It consists of 340 objects (tables, portraits, paperweights, colliers, snuff boxes, brooches, etc.) acquired by the Petochi family in 1993, including works added from the Savelli and Torlonia collections.
TOTAL COST: € 20.344,38 ($ 21,740.00)
State of Preservation
The collection of Roman micromosaics includes some works on display and others in storage. In order to optimize care for the new exhibition, there is a plan to clean the micromosaic works and the metal mounts or frames by the competent laboratory. All the metal elements that complement the works have undergone natural oxidation of the surface, which alters their reading.
Restoration Procedures
- Handling of the works in the laboratory
- Pad degreasing with ketone solvents
- Buffer cleaning and packing of metal parts with Rochelle salts with protection of micromosaic parts
- Finish cleaning with calcium carbonate powder
- Rinsing and dehydration
- Protection with nitrocellulose varnish of metal areas
- Create a new display arrangement
Detail
Inventory N°: Various
Artist: Unknown
Date: Late 18th-early 19th century
Dimensions: Various
Materials: Gold and micromosaics; silver and vitreous paste
Department:
Decorative ArtsLaboratories:
Metals & CeramicsWishbook year: 2024
Micromosaics - Final Restoration Report
The project included restoring the micro-mosaics with metal elements (the 149 listed here) and displaying the entire collection in the new showcases built into 11 cabinets of the Pauline II Gallery.
All the works from the previous display in the rooms of the Pius V apartment had strong double-sided adhesive tape on the back to hold the works to the support. The restorer mechanically removed the adhesive from all the pieces with ketone solvents. As for the restoration of the metal elements, they were all cleaned of the protective products used in previous interventions. The restorer cleaned and strengthened some frames that were damaged with laser welding. If possible, the restorer disassembled the micromosaics to remove dirt without risking damage to the colored waxes of the micromosaics or other materials incompatible with the solvents used to clean the metal elements. Works with silver frames were protected with nitrocellulose varnish to slow down the natural oxidation of the metal.
In the meantime, the curator and the architect who designed the display cases began to study the exhibition, selecting which pieces to exhibit. The 11 display cases available were divided by type: jewelry, snuff boxes, paperweights, monuments, and series. After an insightful study of the documents, the curator decided to test the optical effect in the laboratory to facilitate the complex assembly in the showcase.
The architect prepared a panel to simulate the panels of the display cases to compose what would later be the actual setup. Wooden panels made to accentuate the groups of micromosaics aim to highlight the different cores of micromosaics and facilitate the assembly of individual works. Once the restorer verified the correct arrangement of the works in the display cases, the curator chose a placement that would harmonize the composition. After checking the correct positioning of the 363 objects several times, the curator marked the holes that needed to be drilled in the wooden panels to insert the brackets to support the pieces. Instead of using double-sided tape to secure the works to the display cases, as in the previous exhibition, the curator decided to use brass hooks covered with a rubber grommet so that the metal would not come into contact with the work and damage it.
Since each piece is different in shape and size, this system was designed individually for each piece. Despite this process being time-consuming, it allows the removal of micromosaics from the display cases at any time for study or loan to exhibitions without risk of damage. For this reason, the first display cases, containing more than 100 objects, were assembled at the rate of one a day. Almost every piece is secured with three brass hooks. A hole was drilled in the wood so as not to risk splitting it with just the thread of the hook. These were then screwed in and, after measuring the work, shortened with a pair of pliers so as not to interfere too much with the reading of the work. Transparent thermoplastic tubes were then placed on top of these and, once cut to size, heated to make them adhere. Once cooled, the works could be safely installed.
The micromosaics have all been placed in the display cases, except for four tables on pedestals and one cabinet because they are disproportionate; the tables will soon be placed in front of the display cases, waiting for the carpet to be laid to highlight their relevance to the collection inside the display cases.
Micromosaics - Second Restoration Update
The collection of Roman micromosaics is partly on show, and a part is still in storage. To enhance the new display, the restorers of the Metal and Ceramics Laboratory cleaned the micromosaic and their metal frames, whose surfaces underwent natural oxidation, altering their reading.
All the metal elements that complete the works have undergone a natural oxidation of the surface, which changes their appearance.
The restorers overhauled all the micromosaics and removed the adhesive tapes. All the metal elements that completed the works were cleaned of oxidation that altered their interpretation, and, where possible, they were detached from the works to allow a more thorough cleaning. Two bracelets with broken metal bezels had been soldered with a laser welder to replace the stones and rejoin the links of the bracelets. Restorers performed the same procedure on one of the necklaces. All the silver frames were protected with nitrocellulose varnish to retard their natural oxidation. Once all the pieces had been restored, the final photographs were taken. The architect will soon deliver the new display cases, the color of which has already been chosen. In a week, the micromosaics will be on show in the showcases of the Paulin Room number II. As soon as the lighting and alarm systems have been installed and set up, we will begin to arrange the works in them according to the art historical criteria decided by the Department.
Micromosaics - Restoration Update
Restoration procedures
In 2018, the project for the restoration of the micromosaics, transferred from the apartment of Pope Pius V to the cabinets of the Library converted into 11 showcases, was approved. The conversion of the showcases into display cases is ongoing, and the contracted company is already working on the new internal structures that will house the micromosaics, while the curator, the restorer, and the architect are studying the distribution of the pieces inside the showcases. The Scientific Research Laboratory made an in-depth image analysis of some of the micromosaics to define a restoration protocol to apply to the entire collection. This protocol, which highlights the original parts, the restoration elements, and the nature of the constituent materials, will be applied to all the artworks; this will allow a more in-depth study of the collection by the curator and suggest the restoration methodology to use for each micromosaic without damaging the many works superficially covered with pigments. Some passepartouts are damaged and will be cleaned and laser welded to consolidate them.
Scientific Analysis
The selected investigations involve a campaign of image analysis, mainly infrared in false colors in the spectral range from 850 up to 1000 nm, and chemical mapping of the constituent elements by XRF fluorescence. False-color infrared imaging experimented by the Scientific Research Laboratory gave fascinating data: Non-original tesserae and chemical elements used as chromophores in the vitreous pastes were easily detected. In the case of micromosaics, where the individual tesserae are less than a millimeter, the resolution of the false-color images must be very high. For example, for the micromosaic inventory 53185 of size 70x50 mm, the Scientific Research Laboratory took 84 images to cover the entire work (stitching technique), achieving a final spatial resolution of more than 100 pixels/mm. The possibility of having an image in visible and infrared false colors allows fundamental documentation of the state of conservation. Any restoration intervention changes the material state of the works, and it is essential to have a scientifically valid document of how the work has come to us. Comparing the relatively high number of images required for imaging analysis and the number of works to be studied, it is easy to imagine the amount of information to process. An in-depth chemical analysis will be carried out using, for the first time given the number of artworks to be studied, ultra-high resolution mapping with the MA XRF technique performed by a robotic measuring head that allows X fluorescence measurements in both X and Y axes by programming the area to be studied. This analysis also requires a very high resolution, and measurements at a distance of 80 microns at a speed of 2 mm/sec. X-ray-fluorescence analysis is a non-invasive technique that uses specially collimated X-rays to provide information on various chemical elements.
Micromosaics
Details
Adopted by: The Texas Chapter
Patrons: Joe Pacetti
Inventory: Various
Artist: Unknown
Date: Late 18th-early 19th century
Classification: Micromosaics
Materials: Gold and micromosaics; silver and vitreous paste
Dimensions: Various
Department: Decorative Arts
Laboratory: Metals & Ceramics
Wishbook year: 2024
Description
MEDIUM PRIORITY PROJECT
The Vatican Museums’ collection of micromosaics (also known as miniature mosaics) represents one of the most important collections in the world. It consists of 340 objects (tables, portraits, paperweights, colliers, snuff boxes, brooches, etc.) acquired by the Petochi family in 1993, including works added from the Savelli and Torlonia collections.
TOTAL COST: € 20.344,38 ($ 21,740.00)
State of Preservation
The collection of Roman micromosaics includes some works on display and others in storage. In order to optimize care for the new exhibition, there is a plan to clean the micromosaic works and the metal mounts or frames by the competent laboratory. All the metal elements that complement the works have undergone natural oxidation of the surface, which alters their reading.
Restoration Procedures
- Handling of the works in the laboratory
- Pad degreasing with ketone solvents
- Buffer cleaning and packing of metal parts with Rochelle salts with protection of micromosaic parts
- Finish cleaning with calcium carbonate powder
- Rinsing and dehydration
- Protection with nitrocellulose varnish of metal areas
- Create a new display arrangement
Media
Micromosaics
Restorations Update: Micromosaics - Final Restoration Report
The project included restoring the micro-mosaics with metal elements (the 149 listed here) and displaying the entire collection in the new showcases built into 11 cabinets of the Pauline II Gallery.
All the works from the previous display in the rooms of the Pius V apartment had strong double-sided adhesive tape on the back to hold the works to the support. The restorer mechanically removed the adhesive from all the pieces with ketone solvents. As for the restoration of the metal elements, they were all cleaned of the protective products used in previous interventions. The restorer cleaned and strengthened some frames that were damaged with laser welding. If possible, the restorer disassembled the micromosaics to remove dirt without risking damage to the colored waxes of the micromosaics or other materials incompatible with the solvents used to clean the metal elements. Works with silver frames were protected with nitrocellulose varnish to slow down the natural oxidation of the metal.
In the meantime, the curator and the architect who designed the display cases began to study the exhibition, selecting which pieces to exhibit. The 11 display cases available were divided by type: jewelry, snuff boxes, paperweights, monuments, and series. After an insightful study of the documents, the curator decided to test the optical effect in the laboratory to facilitate the complex assembly in the showcase.
The architect prepared a panel to simulate the panels of the display cases to compose what would later be the actual setup. Wooden panels made to accentuate the groups of micromosaics aim to highlight the different cores of micromosaics and facilitate the assembly of individual works. Once the restorer verified the correct arrangement of the works in the display cases, the curator chose a placement that would harmonize the composition. After checking the correct positioning of the 363 objects several times, the curator marked the holes that needed to be drilled in the wooden panels to insert the brackets to support the pieces. Instead of using double-sided tape to secure the works to the display cases, as in the previous exhibition, the curator decided to use brass hooks covered with a rubber grommet so that the metal would not come into contact with the work and damage it.
Since each piece is different in shape and size, this system was designed individually for each piece. Despite this process being time-consuming, it allows the removal of micromosaics from the display cases at any time for study or loan to exhibitions without risk of damage. For this reason, the first display cases, containing more than 100 objects, were assembled at the rate of one a day. Almost every piece is secured with three brass hooks. A hole was drilled in the wood so as not to risk splitting it with just the thread of the hook. These were then screwed in and, after measuring the work, shortened with a pair of pliers so as not to interfere too much with the reading of the work. Transparent thermoplastic tubes were then placed on top of these and, once cut to size, heated to make them adhere. Once cooled, the works could be safely installed.
The micromosaics have all been placed in the display cases, except for four tables on pedestals and one cabinet because they are disproportionate; the tables will soon be placed in front of the display cases, waiting for the carpet to be laid to highlight their relevance to the collection inside the display cases.
Restorations Update: Micromosaics - Second Restoration Update
The collection of Roman micromosaics is partly on show, and a part is still in storage. To enhance the new display, the restorers of the Metal and Ceramics Laboratory cleaned the micromosaic and their metal frames, whose surfaces underwent natural oxidation, altering their reading.
All the metal elements that complete the works have undergone a natural oxidation of the surface, which changes their appearance.
The restorers overhauled all the micromosaics and removed the adhesive tapes. All the metal elements that completed the works were cleaned of oxidation that altered their interpretation, and, where possible, they were detached from the works to allow a more thorough cleaning. Two bracelets with broken metal bezels had been soldered with a laser welder to replace the stones and rejoin the links of the bracelets. Restorers performed the same procedure on one of the necklaces. All the silver frames were protected with nitrocellulose varnish to retard their natural oxidation. Once all the pieces had been restored, the final photographs were taken. The architect will soon deliver the new display cases, the color of which has already been chosen. In a week, the micromosaics will be on show in the showcases of the Paulin Room number II. As soon as the lighting and alarm systems have been installed and set up, we will begin to arrange the works in them according to the art historical criteria decided by the Department.
Restorations Update: Micromosaics - Restoration Update
Restoration procedures
In 2018, the project for the restoration of the micromosaics, transferred from the apartment of Pope Pius V to the cabinets of the Library converted into 11 showcases, was approved. The conversion of the showcases into display cases is ongoing, and the contracted company is already working on the new internal structures that will house the micromosaics, while the curator, the restorer, and the architect are studying the distribution of the pieces inside the showcases. The Scientific Research Laboratory made an in-depth image analysis of some of the micromosaics to define a restoration protocol to apply to the entire collection. This protocol, which highlights the original parts, the restoration elements, and the nature of the constituent materials, will be applied to all the artworks; this will allow a more in-depth study of the collection by the curator and suggest the restoration methodology to use for each micromosaic without damaging the many works superficially covered with pigments. Some passepartouts are damaged and will be cleaned and laser welded to consolidate them.
Scientific Analysis
The selected investigations involve a campaign of image analysis, mainly infrared in false colors in the spectral range from 850 up to 1000 nm, and chemical mapping of the constituent elements by XRF fluorescence. False-color infrared imaging experimented by the Scientific Research Laboratory gave fascinating data: Non-original tesserae and chemical elements used as chromophores in the vitreous pastes were easily detected. In the case of micromosaics, where the individual tesserae are less than a millimeter, the resolution of the false-color images must be very high. For example, for the micromosaic inventory 53185 of size 70x50 mm, the Scientific Research Laboratory took 84 images to cover the entire work (stitching technique), achieving a final spatial resolution of more than 100 pixels/mm. The possibility of having an image in visible and infrared false colors allows fundamental documentation of the state of conservation. Any restoration intervention changes the material state of the works, and it is essential to have a scientifically valid document of how the work has come to us. Comparing the relatively high number of images required for imaging analysis and the number of works to be studied, it is easy to imagine the amount of information to process. An in-depth chemical analysis will be carried out using, for the first time given the number of artworks to be studied, ultra-high resolution mapping with the MA XRF technique performed by a robotic measuring head that allows X fluorescence measurements in both X and Y axes by programming the area to be studied. This analysis also requires a very high resolution, and measurements at a distance of 80 microns at a speed of 2 mm/sec. X-ray-fluorescence analysis is a non-invasive technique that uses specially collimated X-rays to provide information on various chemical elements.
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