Petrus Biverus's Sacrum Oratorium and Sacrum Sanctuarium (Antwerp, 1634): Balthasar Moretus's Preference for Pearls over Glass.

This article examines the production, costs, and commercial reception of two richly illustrated emblem books published in 1634 by the Plantin-Moretus Press of Antwerp, authored by the Spanish Jesuit Petrus Biverus: *Sacrum Oratorium piarum imaginum immaculatae Mariae* and *Sacrum sanctuarium crucis*. It highlights the tension between Biverus's dissatisfaction with the high selling price of his books and publisher Balthasar Moretus I's need to recoup substantial expenses incurred from purchasing and reworking expensive copperplates and producing high-quality illustrations. Despite Moretus's extensive distribution network across Europe, sales were limited, particularly among Jesuit colleges, resulting in slow returns that barely covered production costs. The article situates this case within broader publishing practices of the time, illustrating the conflicting priorities of authors seeking wide readership and publishers aiming for profitability in the production of elaborate, costly editions.