Let there be light? An investigation into the fading characteristics of the early synthetic dye magenta

Abstract

Magenta, was discovered in 1858 and quickly became the first commercially
successful synthetic dye. It was first synthesized and classified as a basic dye. Basic
dyes have been historically recorded as being highly sensitive to light. Since light is
required to view historic textiles, an issue presents when attempting to strike a
balance between preserving the textile and providing access through display,
examination, study, or conservation treatment. The aim of this research was to
investigate if magenta was as light sensitive as it was historically be reported and if
it is light sensitive in a museum environment.
This investigation evaluated colour and chemical changes within silk and wool
magenta dyed model test fabrics. They were subjected to a range of six different
lighting scenarios chosen to mimic likely lighting scenarios textiles may be exposed
to during display, examination, and treatment. Colour and chemical changes were
evaluated using a spectrophotometer and ultra high performance liquid
chromatography coupled with photo diode array detection (UHPLC-PDA). Results
generated from the study indicate that both colour and chemical changes occur
when magenta is exposed to light.