The Delft Master of Glass: Jacob Willemsz. Delff (I) Jacob Willemsz. Delff, the elder, stands as a pivotal figure in the burgeoning world of 17th-century Dutch glassmaking. Born into a family already steeped in the craft – his father, Willem Janszoon Delff, was also a prominent glassblower – Jacob inherited not only a workshop but a legacy of innovation and artistic ambition. While precise dates surrounding his birth remain elusive, w…