The Black Hours, a book of hours written and illuminated on vellum that was stained or painted black, was probably produced in Bruges about 1475. It is one of seven surviving books of hours on black vellum, all of which were produced in Flemish workshops in the second half of the 15th century. It was illuminated by an unknown artist whose style was largely imitative of that of Willem Vrelant, one of the most prolific, influential, and commercially successful working in Bruges from the late 1450s until his death in 1481.
The text of The Black Hours is written in silver and gold, with gilt initials and line endings composed of chartreuse panels enlivened with yellow filigree. The borders consist of gold foliage on a monochromatic blue background. The artist executed the miniatures in a restricted palette of blue, old rose, and light flesh tones, with dashes of green, gray, and white. He used the solid black background to great advantage, especially by means of gold highlighting. As in the work of Vrelant, figures in angular drapery move somewhat stiffly in shallowly defined spaces. The men's flat faces are dominated by large noses.
The Black Hours is preserved in the Morgan Library & Museum (MS. M.493). In November 2013 an excellent digital facsimile of it was available from the Morgan Library & Museum website.