The Fitzwilliam Library possesses a beautiful example of this class of pen illumination in a large folio volume of the Summa of Aquinas printed by Mentelin about 1465 or 1466.
Mentelin in his youth was an illuminator of manuscripts in Paris at the same time that he was a student in the University; see page [150].
Such work as the Pisan Baptistery pulpit of Niccola Pisano, executed in about 1260, was an almost isolated phenomenon, and it was not till about half a century later that Giotto and his pupils produced paintings of equal merit to those of France and England during the second half of the thirteenth century.
See Mon. Germ. Hist. XII. p. 348 seq.; and Agincourt, Hist. d'Art, Pl. 66.
Partly owing to the necessarily decorative beauty of the glass tesserae, Byzantine mosaics, even of a degraded period, are usually fine and rich in effect.
See Vasari, Vite dei pittori, Edition of 1568, Parte I. p. 229 seq.; and ib. Milanesi's edition, 1878, Vol. II. pp. 17 to 29.