Calcium sulfate fillers and binders in Portuguese 15th and 16th centuries: Ground layers from a family painting workshop ? Study by multianalytical spectroscopic techniques - Antunes, Vanessa; Candeias, Antonio; Oliveira, Maria Jose; Lorena, Merces; Seruya, Ana Isabel; Carvalho, Maria Luisa; Gil, Milene; Mirao, Jose; Coroado, Joao; Gomes, Virginia; Serrao, Vitor (2016)