At the present time, Arca Artium contains well over 30,000 books. Of these, some 3500 are "rare", whether by age, outstanding literary or artistic quality, or limited production. The work of great scribes, printers, illustrators and engravers is represented in manuscripts, early printed books and recent limited editions from fine private presses. Particular strengths:

manuscripts: the collection includes the fourteenth-century Greek and Arabic Kacmarcik Codex, a particularly fine fifteenth-century Latin Book of Hours of the Sarum use, and several medieval monastic charters;

printed Bibles: incunable Bibles (Naples: Moravus and Romero, Cologne: Götz, 1480; Strassburg: Rusch for A. Koberger, 1481; Venice: Renner de Heilbronn, 1482); the Plantin Polyglot of 1571-72; several early printed Greek New Testaments (including Estiennes); several Baskerville Bibles; the Doves Press Bible of 1903-05, and many Bibles of the 16-20th centuries significant for their illustrations;

incunabula (printing before 1501): the several Bibles listed above, important theological and monastic texts (such as the first printed edition of John Cassian's Conferences, Brussels: Fratres vitae communis, 1476), and dozens of single pages;

hundreds of significant books by historic printers such as Froben, Aldus, Colines, Estienne, Plantin, Barbou, Didot, Baskerville, Bodoni;

books from modern private presses such as Chiswick, Doves, Nonesuch, Golden Cockerell, and books designed by Eric Gill and printed by H.D.C. Pepler at Ditchling; books designed by Bruce Rogers, Rudolf Koch, Stanley Morison, Frank Kacmarcik and many others.

The reference collection of some 28,000 books includes important works on typography and book arts, art theory, book production, liturgical and monastic art, architecture, drawing, painting, print-making, calligraphy, photography, folk arts. Arca Artium includes complete runs of many significant journals in various artistic fields.