Plantin’s printer’s mark from Girolamo Ruscelli’s compilation of medical and other recipes, “Secreti,” (Secrets). Title given in the French edition as “Les secrets du seigneur Alexis Piemontois, et d’autres auteurs bien experimentés et approuvés, reduits maintenant par lieux communs, & diuisés en six liures pour la commodité de ceux qui en voudrót user.” (The secrets of the Lord Alexis of Piedmont, and other authors, ably tested and approved, now condensed according to common themes, and divided into six books for the convenience of those who would like to use them). Plantin was also known for his use of various kinds of elegant typeface including Garamond.
A Anvers: Impr. de C. Plantin, 1564, https://lccn.loc.gov/44010677.
PDF http://hdl.loc.gov/loc.rbc/bitting.02380.2,
page view http://hdl.loc.gov/loc.rbc/bitting.02380.1.