the “Breve tratado de Iluminação”, an anonymous manuscript without date and whose author would have been from the Order of Christ. The manuscript is original, except for one chapter which was actually copied from the “Arte da Pintvra” by Philippe Nunes. It is composed of 88 folios and has not yet been published. Several references, however, to the techniques of many artists were found such as a varnish recipe used by El Greco and the description of the preparation of a panel by painters Vasco Fernandes and Luz Morales. Vitor Serrão, Professor at FLUL, spoke about pigments used in paintings from the XVI (16) and XVII (17) centuries and referenced in Portuguese contracts