Decoding a drawing: The stained-glass color scheme of the altar of Igreja de Nossa Senhora de Fátima

In the process of cataloging the estate of modernist artist Almada Negreiros, many preparatory drawings for several of the author's public artworks are currently being identified. The volume and complexity of his prolific work imply that sometimes it is hard to connect specific documents and artworks of research and preparation to their respective final works. Recently, one particular drawing proved to be the key for understanding several other documents, simultaneously contributing to clarify the artist's methodology when preparing for the large-scale stained glass behind the altar of Igreja de Nossa Senhora de Fátima. This article presents these new advances.