P. P. RUBENS, by, Frans Baudouin, translated by Elsie Callander (Abrams, $60). Here is a book on Rubens that is as richly illustrated as the baroque paintings of Rubens are opulent - of the 278 illustrations, 96 are in gorgeous color. Frans Baudouin, the curator of the Rubens House in Antwerp, has written a general introduction to Rubens, followed by 15 essays which go into greater depth about his life and work. He deals with the altarpieces from teh period 1609 to 1620, the Flagellation of Christ in the Church of St. Paul in Antwerp, as well as the artist as a man and a thinker.

RUBENS AND ITALY, by Michael Jaffe (Cornell University Press, $55), will interest more the scholarly than the lovers of handsome books. Yet its topic is intriguing. In dealing with the formative period of the young Rubens, 1600-08, when the artist went to Italy and briefly to Spain, Jaffe attempts to answer to questions: "How much did this Flemish painter absorb of Italy, and how did Italy respond to him? How deliberate, or how chancy, was the intricate process of mutual assimilation?" The answers are important not only for Ruben's biography and artistic development, but they also serve to put in focus the complex interplay between Flemish and Italian art that was so strong between the early 15th and late 17th centuries. With only 16 color plates among its 352 illustrations, the cost of this specialized knowledge is fairly high; but the work is stimulating.