Grolier lived in Italy, with only a few interruptions, between 1510 and about 1525, and, while there, became the friend of the celebrated printer, Aldus Manutius. It is said that in appreciation of Grolier's friendship and financial assistance, Aldus printed several copies on vellum or large paper for Grolier, several of which were dedicated to him.
Grolier is believed to have patronized several binders over the years he collected, including Claude de Picques, and the so-called fleur-de-lis and cupid's bow binders.
The books which Grolier acquired in his early years (including many of his Aldine volumes) possess the distinguishing characteristics of Italian binding of the time he lived in Italy.
The Grolier bindings, the designs of which have been imitated more than those of any other style, with the possible exception of the pointillé bindings, are usually classified into two distinct groups: 1) those executed expressly for him; and 2) those bound before he acquired them either through purchase or gift.
Although the bindings executed for Grolier are distinctly similar in style, they vary considerably in their ornamentation. The designs generally consist of a geometrical pattern, occasionally colored, combined with arabesque work, which is solid, azured, or only outlined. On some of his bindings, however, the geometrical pattern has no arabesques, while in others the arabesque work is found without the geometrical design. Nearly all of the books of the first class, as well as many of those of the second, include the altruistic inscription, lo. Grolierii et Amicorvm (of Jean Grolier and his friends), usually at the tail edge of the upper cover, which he apparently borrowed from his contemporary, Mahieu. Both covers of most of Grolier's bindings feature a central compartment, usually containing the title of the book on the upper cover, and the expression Portia Mea, Domine, Sit in Terra Vivetivm (Let my portion, O Lord. be in the land of the living), on the lower cover. Other legends also at times appear on his bindings.
Grolier's signature, or his motto, with several slight variations, is frequently found in his own hand inside the books he collected before about 1536. This was usually written at the back.
There are two distinct features to Grolier's bindings which were not consistently practiced by other contemporary collectors: 1) the pastedowns are vellum, followed by two conjugate white pa?er flyleaves, which are followed by a vellum leaf conjugate with the pastedown, which is followed by a final conjugate pair of paper leaves; and 2) the edges are gilt but not gauffered or otherwise further embellished. See PLATE IV . (59 , 132 ,141 , 245 , 273 , 279 , 285 , 347 )