Description du projet :
For generations, humanity has preserved customs, places, objects, artistic expressions and values creating our cultural heritage. The use of colour on cultural heritage objects is ubiquitous and found on artefacts from prehistoric times onward. Aside from paintings, colourants are found in polychrome sculptures, postage stamps, as dyestuff in historical textiles, colored glazes in varnish or in the lacquer of music instruments and furniture. The chemical identification of the colouring materials used on an artwork often provides information about the work's origin such as its geographic location, and historical period. At the simplest level, a comparison of the materials present with information on their first date of discovery can indicate the earliest possible period in which the artefact was created. More precise constraints on the date
and origin of creation can be provided by radiocarbon (14C ) dating and stable isotope analysis, however until today no such analysis has ever been conducted solely on organic colourants within an object.
The proposed project has been inspired by my past 6 years working at the frontier of 14C dating and heritage science. In particular by experiencing the problems raised in dating precious works of art, often resulting from the methodology or from issues regarding the targeted materials. A recurring keyword in describing cultural heritage objects is complexity, as these items are composed of a wide array of materials combined in an infinite number of ways, colour, being almost invariably present. Here, I propose to focus on the colorants, that were purposely chosen by the artist and thus relate to the crafting of the object itself. The novelty of this project is to develop new metrics for assessing the origin of an artwork founded on the principles that i) the carbon backbone of natural organic dyes stores a wealth of information regarding its source and origin and ii) this information may be retrieved by capitalizing on compound specific analysis as opposed to bulk sample analysis. To reach these objectives the PI will demonstrate the potential of natural organic colourants as dating
proxies through the development of a compound specific radiocarbon analysis (CSRA) methodology targeting dyed textiles. In parallel, the requested postdoctoral researcher will evaluate how variations in stable isotope composition (ä13C, ä18O and äD) in madder and indigo plant species relate to their geographical regions of growth.
The overreaching goal of this project is to pioneer the development of compound
specific isotopic analysis approaches tailored to the needs of heritage science.
Specifically, I aim to study art objects at their molecular level before fingerprinting
their isotopic composition. By drawing on the knowledge gained from art technology research and advances in compound specific isotope analyses, the PhD student will have all the cards in hand to selectively 14C date the natural organic lake and separately the paint binder within the same microsample. From paint materials, alongside with the postdoctoral researcher, the PhD student will refine the methodology further to address the multi-layered varnish system in historical stringed instruments, while the PI will focus on Swiss postage stamps. The development of these new metrics will foster groundbreaking research at Swiss national institutions, contributing to Switzerland's role as a leader in the growing field of heritage science.
Research team within HES-SO:
Rumpf Lionel
, Hendriks Laura
Partenaires académiques: Sönke Szidat, Bern University
Durée du projet:
01.03.2024 - 29.02.2028
Montant global du projet: 934'353 CHF
Statut: Ongoing