Among the holdings of the Solomon R. Guggenheim Foundation, New York, is a large-scale portrait by Édouard Manet that remained apparently unfinished upon the artist’s death, in April 1883. This work, now known as Woman in Striped Dress, belongs to Manet’s late artistic production and dates from around 1877 to 1880. A collaborative endeavor entailing archival research and scientific analysis revealed that the composition had suffered dramatic alterations prior to its arrival at the museum in 1965 as an extended loan, likely carried out to “finish” the picture in order that it would be marketable and to increase its sale value. Among the main changes explored in this technical study are the reductions in the canvas size and subsequent varnish...