Let there be light? An investigation into light-induced changes of the early synthetic aniline dye magenta under indoor lighting conditions

A major development of the 19th century was the discovery of synthetic textile dyes. Magenta, also called fuchsine, was on the market in 1859 and gained major commercial success despite its known high sensitivity to daylight. Magenta proved to be a fashionable and useful color until the end of the 19th century and is therefore present on many museum textiles from this period. Since light is essential for viewing, color preservation of magenta-dyed textiles is a challenge when the definition “highly sensitive to light” is unclear. Additionally, accounts of magenta fading are historical and describe exposure to sunlight, not modern controlled collection lighting. This paper shares the results of an investigation into the light-induced changes of magenta-dyed textiles exposed to indoor lighting environments. Silk and wool fabrics dyed with commercial magenta (basic form) were exposed in real time to different lighting scenarios for six weeks. Changes were measured using a spectrophotometer and ultra high performance liquid chromatography coupled with photodiode array detection (UHPLC-PDA). Results indicated that lighting, even in “safe” workrooms and controlled displays, can induce changes in magenta. This is the first known reported evidence of real-time magenta color change under indoor lighting conditions