The Raphael Court during the recording © Gabriel Scarpa for Factum Foundation
In August 2019, a team of 3D-scanning and photography specialists from Factum Foundation carried out the recording of the Raphael Cartoons at the Victoria and Albert Museum in London. The cartoons constitute probably the most important series of artworks from the Italian Renaissance in the UK and are on long-term loan to the Museum by Her Majesty the Queen from the Royal Collection.
The tapestry cycle was commissioned from Raphael and his workshop by Pope Leo X in 1515. The series was destined for the Sistine Chapel in the heart of the Vatican, and the ten designs depict the lives of the apostles Saint Peter and Saint Paul. While the ten final tapestries have survived, although they are rarely on display, only seven of the preparatory cartoons are still extant. These reappear in the record in 1623 within the collection of King Charles I, and since 1865 they have been displayed in the Raphael Court of the V&A Museum.
This project was one of Factum Foundation’s most ambitious digitisation projects to date and has set new standards for large-scale, high-resolution digital documentation of low-relief surfaces. It employed non-contact digital technology to capture detailed information for the surfaces of the seven monumental Cartoons and provided the original and processed data to the V&A for study and dissemination.
In order to complete the recordings, a team of specialists from Factum Foundation worked around the clock in three shifts for a period of five weeks, during which time the gallery was closed to the public. By following a carefully planned schedule it was possible to coordinate the recording of the Cartoons with the removal and replacement of the vast frames, the production of conservation condition reports, and other tasks carried out by the Museum’s staff. Fluent communication and coordination between the different teams was key to the success of the recording phase of the project.
The Momart team removed the frame of each Cartoon before the recording began © Factum Foundation
[R] The frame of each Cartoon had to be carefully removed by the Momart team before the recording © Elizabeth Mitchell for Factum Foundation
[L] A V&A conservator condition checks a Raphael Cartoon © Photo: Victoria & Albert Museum, London
In the first phase of the project, a total area of about 115 square metres was digitised using two complementary non-contact methods: high resolution panoramic photography, which was used to record both colour and infra-red, and the Lucida 3D Scanner.
Conceived and developed by artist and engineer Manuel Franquelo with Factum Arte, the Lucida 3D Scanner is a close-range, non-contact laser recording system that captures high-resolution surface texture data for low-relief surfaces. It allowed the meticulous recording of surfaces which, while apparently flat, are in fact remarkably complex, made up of composite sheets of paper and showing the evidence of the painting process, pouncing, folding, and previous restoration treatments. This coherent high-resolution data can be used for accurate condition monitoring and for study.
The Lucida records 3D data in 48 cm x 48 cm 'tiles' by projecting a moving laser beam onto the surface of an artwork. The beam is distorted as it moves across the surface and this data is captured by two video cameras positioned at 45° to the laser. The black and white video is automatically processed by the integrated scanner software to produce a render – an 'image' of the 3D surface, which is used to generate the 3D model. The system is entirely non-contact and the scanning head is always at least 8 cm from the surface of the artwork.
The Lucida 3D Scanner recording the surface of a Raphael Cartoon at the V&A © Gabriel Scarpa for Factum Foundation
The Lucida 3D Scanner is entirely non-contact and operates at safe distance from the artwork at all times © Factum Foundation
To produce accurate digital records of the Cartoons, four Lucida 3D Scanners were employed simultaneously to record the relief at a resolution of 100 microns (generating render images at 254 dpi at 1:1 scale). The scanners were mounted on scaffolding towers, reaching a maximum scanning height of about 5.5 m. The stability of the scaffolding, built by Momart, was essential to guarantee the highest level of safety for the cartoons and to produce optimal data quality.
At night, the Raphael Court was animated by the flash of hundreds of photographs, part of the process of panoramic photography. Factum’s photographers have spent many years perfecting this technique, which they use to create high-resolution colour recordings of a flat or gently undulating surfaces.
Recording the colour of the Raphael Cartoons at the V&A using panoramic composite photography © Gabriel Scarpa for Factum Foundation
Many people are familiar with the basic concept of panoramic photography in which overlapping photos are stitched together to create a composite image. Factum uses panoramic photography to produce images of cultural heritage objects with resolutions of up to 900 dpi, following a set procedure to ensure the accuracy of the colour data. The process involves both digital colour checks using X-Rite colour checking methods, and physical colour checks using Pantone charts and specially made 'colour sticks', which are matched to the colours on the painting. These checks are especially important in the production of facsimiles, ensuring accurate colour and tone and a close correspondence between the recording, the re-materialisation and the original painting.
During the photography process, flashes are used to evenly illuminate the surface of the artwork. The camera normally remains fixed, while the position of the flashes is changed at least 3 times.
The cartoons were recorded in colour and infra-red at a resolution of 400–450 dpi at 1:1 scale.
Recording the colour of the Raphael Cartoons at the V&A using panoramic composite photography © Gabriel Scarpa for Factum Foundation© Gabriel Scarpa for Factum Foundation
The second phase involved processing the digital information captured on-site to render it suitable for different applications. During late 2019 and 2020, the raw files were carefully analysed, edited and stitched together to create the high-resolution composite images. Since the 3D data recorded by the Lucida system is generated as a greyscale depth-map and shaded image renders, it is possible to employ image-based software like PTGui to align the tiles; a similar semi-automatic process is followed with the photography and infra-red images. As a result of these stitching operations, three panoramas are generated for each Cartoon: a 3D render (which is used as a base), a colour file and an infra-red file.
Viewing high-resolution files like these on an ordinary computer can be problematic: simply to open a file of 40GB (the size of one of the panoramas) or to compare three different datasets would be extremely memory-intensive. But this is a critical part of the work – multi-layered navigation of different types of data is key to understanding the surface of complex artworks like the Cartoons. To make this possible Factum has produced a multi-layered browser that is easy to use and can be accessed via the internet. Paintings and other low-relief artifacts can now be studied and shared as the complex subjects that they are, in ways that render their historic trajectories evident and traceable. This ability to focus on a specific detail and to turn the different layers (relief, colour and infra-red information) off and on in an intuitive way constitutes a new way of approaching the study of paintings and works of art.
Factum software engineers are continually working to improve the automated processing of data: to speed up the process, improve alignment, and understand and exploit the potential of the cloud in which the data is stored and through which it is processed. Due to their scale, the recording, processing and output of data from the Raphael Cartoons has proved a stimulus to this development, opening the field for new reflections on the future role of AI and machine learning in the preservation of cultural heritage.
Creating the infrared layer. RAW file from camera (left) and after the RAW development (right). © Factum Foundation for the V&A and Royal Collection Trust
The scanned tiles of a Cartoon. In light grey, the overlap areas between the different tiles. After this phase, Factum’s experts create a depthmap containing the 3D information of the relief of the painting. This file is then used for CNC-milling or handed over to Canon Production Printing, Factum’s long-term partner who uses its elevated 3D printing technology, which then serves for the production of a physical facsimile. © Factum Foundation for the V&A and Royal Collection Trust
Accurate recordings are essential for the production of an exact facsimile. A facsimile should be identical to the original under normal viewing conditions. They can be used for preservation and dissemination of the original and they are increasingly being used as a new way to share, reunite and experience culture. The Cartoon depicting The Sacrifice at Lystra has been rematerialised as a facsimile for the exhibition 'Raffaello (1520-1483)' at the Scuderie del Quirinale in Rome, for which Factum Arte also rematerialised the tomb of Raphael (the original is in the Pantheon).
To make the facsimile, the surface relief of the painting was first printed in 3D using the elevated printing technology developed by Canon Production Printing, a Canon company with whom Factum Foundation has collaborated on many projects. CPP’s revolutionary printing method involves building up relief in 5-micron layers to replicate the exact surface of a painting.
In Factum’s workshops, liquid silicon is then poured over the relief print to create a mould of its surface. A cast is then made from this mould using a specially prepared acrylic gesso mix. This ‘skin’, which forms the base surface of the final facsimile, is then fixed to a backing canvas in a process that is similar to re-lining a painting. In the case of The Sacrifice at Lystra, a CNC-milled polyurethane panel imitating the undulations of the original was used as support.
Factum’s purpose-built flatbed printer has been designed in-house to print in multiple layers across large surfaces. Using a traditional method of registration, the colour and the relief are perfectly aligned, ensuring that the appearance of the facsimile is entirely faithful to the original. Multiple layers of over-printing ensure that the tone and hue or each colour is exact. The final stage is varnishing and hand finishing. In the exhibition in Rome the facsimile is on display at eye level and without glass. The experience of seeing the tapestry and the Cartoon side by side opens many new avenues for study.
Once all printed panels are joined together the seams are made invisible. © Otto Lowe for Factum Foundation
The facsimile within the exhibition spaces of 'Raphael ()'. Picture by Alberto Novelli © 2020 Scuderie del Quirinale - Ales
The facsimile within the exhibition spaces of 'Raphael (1520-1483)'. Picture by Alberto Novelli © 2020 Scuderie del Quirinale - Ales