The great missals of the 15th and 16th centuries were monuments of printing—books that carried the Catholic Mass through centuries of ritual. Most were read to pieces. Very few survive complete. We are offering one of those survivors: a 1521 Roman Missal printed in Paris by Thielmann Kerver, the leading printer of liturgical texts in early Renaissance France. Printed in red and black with Gothic type, woodcuts, and musical notation, it represents the Catholic rite at the dawn of the Reformation.