According to Thomas Kren, a former curator of the J. Paul Getty Museum, the miniatures within the Spinola Hours can be attributed to five distinct sources.

Margaret of Austria, daughter of Mary of Burgundy and Governor of the Habsburg Netherlands from 1507 to 1515, is one possibility, as some of the artists had worked for this major patron.

In addition, Gerard Hourenbout, a court artist who illuminated the Sforza Hours and served under Margaret of Austria, was either the same person as, or was at least associated with, the Master of James IV.

The Royal Library of Belgium was prepared to bid up to $500,000, but the dealer Hans P. Kraus secured it for $750,000 (£370,000), at the time "a staggering figure for such a late book of hours".

The manuscript is bound in eighteenth-century dark red leather with a gold floral border on both front and back covers.

The first three-quarters of the Spinola Hours reflect visible artistic consistency; however, anomalies in the gatherings and inconsistencies in border size start to appear closer towards the end of the book.

Some of the borders framing the text pages imitate carved wood or textiles, but most have the usual flowers, berries, and insects, here very carefully depicted.

These have several different parts: at the bottom a wide scene showing the relevant Labour of the Month, below the "window" with the actual calendar, then along one side a set of roundels with small scenes in color illustrating the notable feats of the month, and at bottom a roundel with an image of the relevant sign of the Zodiac, which is named below.

The artists from the workshop of the Master of the First Prayerbook of Maximilian made the second largest contribution to the miniatures in the book, creating twenty-four.

There were more distinct pink tones in the skin, large broad heads, and exhibited no gray undertones often found in his illuminations.

92v) illustrated by the Master of James IV, showcases a framed panel in a special red text "incipiu[n]t hore beate marie virginis secundu[m] usu[m] Romanu[m].

The Holy Trinity Enthroned (fol.10v) is one of the earliest fully painted illustrations featured in the Spinola Hours by the Master of James IV.

Each of the three figures is distinguishable from the waist up but share only one robe, this symbolism is part of the Christian belief that Trinity is made up of three persons and one substance.