Hexagrams appear in the printer’s mark of Jacobus Bellaert from 1483- “the arms above the Griffin are those of the city of Haarlem”.
Picture copied from Gutenberg project: Printers' Marks, a Chapter in the History of Typography by William Roberts, 1893
Coat of arms of Haarlem, the capital of the province of North Holland
From Wikipedia Commons courtesy of Mcke
