In 1924, a waistcoat knitted in fine blue silk said to have been worn by King Charles I on the scaffold in 1649 was donated to the Museum of London (inventory number A27050). This royal undergarment has been the subject of studies over the years, often with a focus on the stains on its front, and there have been attempts at drawing up a pattern and making a reproduction.

Over the last 18 months, the waistcoat has been the focus of an interdisciplinary project, aimed at broadening our knowledge of this iconic object. This was prompted by the garment’s exhibition in 2022-23, its planned display in the new London Museum in 2026, as well as recent developments in the scientific analysis of textiles. This time, the stains have not been in the spotlight, but rather the waistcoat’s provenance, the materials used, its construction and date of origin.

Using relatively recent online resources, claims for the complex provenance of the waistcoat have been checked. The garment has been systematically examined and described according to the Knitting in Early Modern Europe protocol for knitted items, and comparative garments (including very similar damask examples in Scotland and Oslo) have been considered. Small samples of the royal relic have undergone radiocarbon dating and methods of dye analysis have been combined to determine the source of the garment’s colour. Microfading testing, undertaken mainly to inform future display lighting, provided further information about dyes.

Collaboration with craftspeople enabled the testing of assumptions about how the garment was made. This included the evaluation of silk threads commercially available today to see how they relate to the original material used, and how they behave when undertaking a partial reconstruction.

In this talk, Beatrice Behlen will present some of the study’s findings, but also discuss the challenges, as well as the joys, of collaborating with colleagues from different fields and of working outside her comfort zone.