Historic dye analysis: method development and new applications in cultural heritage

A review of the main natural dyes (particularly yellow flavonoids and red anthraquinones) and proteinaceous substrates used in Historical Tapestries and North American porcupine quill work was undertaken, and is summarised in Chapter 1. The analysis of natural dyes which have been used on museum artefacts other than textiles has received little systematic study, particularly those of non-European origin. In this research, the use of Ultra Performance Liquid Chromatography (UPLC) for study of natural dyes found on historical textiles and ethnographical objects decorated with porcupine quill work is explored; this required a transfer of existing analytical protocols and methodology. The advantages of using Ultra Performance Liquid Chromatography (UPLC) was evaluated through a method development based on the separation and quantification of ten flavonoid and anthraquinone dyes as described in Chapter 2. These methods were then applied to the characterisation of the dye sources found on a group of sixteenth century historical tapestries which form an important part of the Burrell Collection in Glasgow and are believed to have been manufactured in an English workshop (Chapter 3) and also to the analysis of some late nineteenth century North American porcupine quill work from a collection owned by National Museums Scotland (Chapter 5); allowing exciting conclusions to be drawn in each case about the range of dyestuffs used in their manufacture. The second aim of this research was the development of methodology for the non-invasive quantification of metal ion residues on porcupine quill substrates. This was achieved through a comparative study of reference porcupine quills prepared in-house with dyebaths containing a range of metal ion concentrations (copper and tin). The concentration of metal ions sorbed by the porcupine quills was then quantified with Inductively Coupled Plasma (ICP) coupled to Optical Emission Spectrometry (OES) and non-invasive Particle Induced X-Ray Emission analysis (PIXE) coupled with Rutherford Backscattering Spectrometry (RBS) as described in Chapter 4. The responses provided by the different methods were compared and they were then applied to the study of micro-samples collected from mid-nineteenth century Northern Athapaskan porcupine quill work. Unexpectedly, the use of UPLC analysis and RBS-PIXE analysis allowed the characterisation of traded European natural dyes used with metallic mordants (copper and tin) on these samples, highlighting how European contact impacted on traditional Athapaskan porcupine quill work in the late nineteenth century (Chapter 5)

An Inca silver figurine at National Museums Scotland: Technological study [En línea]

The hollow silver male miniature figurine from National Museums Scotland is one of the tallest specimens made in precious metals attributed to the Incas. In spite of showing the expected characteristics of this type of Inca production for ritual offerings —regular proportions and standing pose, representation of its gender, bulging cheek associated to coca leaves chewing and elongated earlobes— this figurine differs from the regular figurines by the form of the top of its head. In addition, the skilled decoration includes details such as well portrayed feet. The technologies and the alloy employed in its manufacture were examined using a stereo microscope and by non-destructive X-ray fluorescence analysis. Comparison between this figurine with the hollow silver male figurines of equivalent stature and typology kept at Dumbarton Oaks Research Library and Collection and Museum of America shows that they are all made with the same technology and by employing silver alloys with copper contents below 0.5%. These alloys are richer in silver than the majority of the alloys employed to fabricate normal Inca hollow figurines of known provenance or from other museum collections

An optimised small-scale sample preparation workflow for historical dye analysis using UHPLC-PDA applied to Scottish and English Renaissance embroidery

A sample preparation workflow for historical dye analysis based on 96 well plates and filtration by centrifugation was developed. It requires less sample and the introduced error is decreased, making it useful for culturally important objects. A sample preparation workflow for historical dye analysis requiring less sample has been developed. Samples as small as 0.01 ± 0.005 mg have been successfully analysed and high percentage recoveries (>85%), more automation and shorter preparation time have been achieved using filtration by centrifugation and only one manual transfer. The optimised workflow based on 96 well plates together with the shorter UHPLC method developed makes dye analysis data collection faster from unprocessed sample to result, facilitating the creation of larger datasets and application of chemometric approaches. The method was evaluated on 85 samples from 12 dye sources (RSD < 5.1%, = 5) as well as 22 samples from a 17 century embroidered stomacher from the National Museums Scotland (NMS) collection

Pests or prey? Micromammal species within an ancient anthropic environment at the Norse settlement site of Tuquoy (Westray, Orkney)

Excel file with five tables containing Tuquoy micromammal data (four tables) and references from Andrews 1990 (one table)

Characterisation of metallic mordants in Subarctic Athapaskan quillwork: a PIXE-RBS study on replicate samples

Native American quillwork collections remain little studied due to the limited availability of quillwork material for sampling. In this paper we explore the use of non-invasive Particle Induced X-Ray Emission (PIXE) and Rutherford Backscattering Spectrometry (RBS) to characterise metallic residues in a set of modern porcupine quills prepared with a range of metallic mordants. PIXE analysis was used to determine the concentrations of various mordants present, while RBS analysis allowed additional information on the depth-profiling of the mordants at the surface of the quills to be obtained.Les collections nord-amérindiennes décorées avec la technique de la teinture des piquants de porc-épic restent très peu étudiées, en raison de la difficulté de prélever ce type de collections. Dans cet article, nous explorons l’utilisation de l’analyse par faisceau d’ions (PIXE-RBS) pour la caractérisation de résidus métalliques sur des piquants de porc-épic de référence préparés en laboratoire avec différents mordants. L’analyse PIXE nous a permis de caractériser les concentrations de mordants métalliques présents à la surface des piquants de porc-épic, tandis que l’analyse par rétrodiffusion de Rutherford (RBS) nous a permis d’obtenir des informations complémentaires sur la répartition de ces mordants dans les couches superficielles de la kératine

Technological study of gold jewellery pieces dating from the Middle Kingdom to the New Kingdom in Egypt

This paper presents a technological study of items of Egyptian jewellery from the collections of the National Museums Scotland: a pendant from the 19th century BC; objects from the 16th century BC royal burial unearthed at Qurneh; two gold finger-rings dated to the 14th century BC; and a group of pendants from the 13th century BC. The objects were examined using optical microscopy, X-radiography and Scanning Electron Microscopy (SEM). In addition, the elementary compositions of alloys and solder joints were investigated using air-path X-ray fluorescence (XRF), proton-induced X-ray analysis (micro-PIXE), and energy-dispersive X-ray analysis (SEM-EDS). This preliminary study provides information about the evolution of alloy composition and the use of alluvial gold, and illustrates the Ancient Egyptian goldsmiths’ skills in working with wires, granulation and joining techniques.Cet article présente l’étude technologique de pièces égyptiennes d’orfèvrerie faisant partie de la collection des musées nationaux d’Écosse : un pendentif daté du xixe siècle av. J.-C., des pièces d’orfèvrerie provenant de la tombe royale de Qurneh datées du xvie siècle av. J.-C., deux bagues datées du xive siècle av. J.-C. ainsi qu’un groupe de pendentifs datés du xiiie siècle av J.-C. Les objets ont été observés sous microscopie optique, par radiographie de rayons-X et par microscopie électronique à balayage en mode électron secondaire (MEB-SE). En parallèle, la composition des alliages et des soudures a été déterminée par fluorescence des rayons-X (FX), par analyse par faisceaux d’ions (micro-PIXE) et par énergie dispersive de rayons-X (MEB-EDS). Cette étude préliminaire donne des informations sur l’évolution des alliages ainsi que sur l’utilisation d’or alluvionnaire, et illustre les techniques utilisées par les orfèvres de l’Egypte Ancienne, en particulier l’utilisation du filigrane, de la granulation et des techniques de soudure

Les costumes des élégants d’Antinoé conservés au musée des Tissus de Lyon : approche historique, analyses techniques et analyses de colorants

L’exposition Antinoé, à la vie, à la mode. Visions d’élégance dans les solitudes, organisée par le musée des Tissus en 2013, en partenariat avec le musée du Louvre, a permis de révéler la presque totalité du produit des fouilles de la campagne de 1898 sur le site d’Antinoé. Toutes les étoffes issues de cette campagne avaient été envoyées à Lyon, et oubliées dans les réserves du musée des Tissus. Pour la première fois, des costumes complets et des fragments de vêtements remarquables, provenant des quartiers de la nécropole où reposaient les fonctionnaires impériaux et la haute bourgeoisie de la cité antique, ont été présentés au public. Les costumes les plus exceptionnels, qui ont fait l’objet d’une analyse technique approfondie, ont également pu servir à caractériser les colorants employés à l’époque byzantine pour la production de luxe. Les analyses de colorants, effectuées par le Musée national d’Écosse et l’université d’Édimbourg, ont caractérisé notamment des rouges précieux (cochenille d’Arménie, kermès), des jaunes de flavonoïdes rares (bois de fustet) et des procédés tinctoriaux subtils (garance et indigo ou gaude, par exemple).On display in the exhibition “Antinopolis : Beyond Life, Beyond Fashion – Shadows of Elegance in the Desert”, organized by the Musée des Tissus, Lyon, in 2013, in partnership with the Louvre, were almost all of the articles uncovered in the excavations on the site of Antinopolis in 1898. All the fabrics found in these excavations were sent to Lyon, stored away in the Musée des Tissus, and forgotten. In this exhibition, complete costumes and fragments of remarkable garments, from the parts of the necropolis where imperial officials and members of the ancient city’s upper-middle class were buried, were shown to the public for the first time. The most exceptional costumes, which were subjected to an in-depth technical analysis, also enabled us to characterise the dyes used in the Byzantine period in the production of luxury fabrics. Notably, dye analysis carried out by National Museums Scotland and the University of Edinburgh showed the use of precious reds (Armenian cochineal, Kermes), rare flavonoid-rich yellows (young fustic) and subtle dye processes (using madder and indigo or weld, for example)