Joannes Masius
Jan Maes or Joannes Masius (active 1566–1615) was a printer and bookseller in the university town of Leuven in the Habsburg Netherlands. Career. Masius, a native of Leuven, is first recorded as working for Christopher Plantin at the Plantin Press in 1566. In 1570 he was licensed as a printer in the city of Leuven. One of his sons, Joannes Masius the Younger, became a printer-bookseller in Ath; another, Bernard or Bernardin, took over his business in Leuven in 1616.