The most common book to survive from the late medieval period is the Book of Hours. These books are collections of prayers for private devotional use rather than for liturgical use or the Divine Office. Almost all were produced in commercial workshops, and although many were written for rich patrons, more humble examples were written for small merchants or craftsmen. Over time the general example became rather stereotyped, with 6, 12, or 24 full-page miniatures, depending on the purse of the patron. Like Psalters, many Books of Hours can be localized because of the inclusion of local saint's feast days in the calendar and the form of liturgical use in the various Offices. The illumination of this Book of Hours is quite unusual, as the drawing is extraordinarily delicate and the colours are unusually light. There are ten full-page miniatures in the calendar and nine three-quarter–page miniatures, all within borders of flowers, amoretti, insects and animals, many of which can be identified.