Flavie Delort is a Chemical engineering student at Chimie ParisTech, part of PSL University, specialising in materials of cultural heritage and sustainable materials. Throughout an internship in VICARTE at FCT-NOVA, she studied the 19th-century manufacture of geranium lake pigments of French production and the fabrication techniques of hand-painted magic lantern glass slides. The French manufacturer Lapierre mass-produced magic lantern glass using, among others, geranium lake colours. Yet, there is no documented evidence of their presence in the red colours of Lapierre's historical slides, and Flavie’s research aims to shed light on this captivating mission.