What little we know about Mast are the notes related by Karel van Mander in his Schilder-boeck, who mentioned him as part of a long list of pupils of Frans Floris.
[1] The next day Mast showed it to his colleague Gortzius Geldorp and told him about what his master said, boasting "Zeuxis's birds!
[1] Van der Mast travelled to Paris where he lived for two years with the Archbishop of Bourges, for whom he painted a Saint Sebastian surrounded by all manner of herbs, that impressed the king's own personal physician.
[1] He then went to live with Monseur de la Queste, knight, president, en procureur-general of the King of France, for whom he worked for seven years.
[2] In his work on Van Mander, Hessel Miedema was able to discover that Mast paid an admission fee for the Delft Guild of St. Luke in the year 1589 for 1587, and was chairman there in 1593.