A portion of a manuscript on vellum. It was originally a leaf from a liturgical manuscript, likely written in France in the 15th century. The leaf was re-used in an edition of the , liklely in France after 1582, which used red and black ink. The sheet (of which this is not the entire part) was used to mask the part of the former, which had been inked red, but which were not intended to be printed in red in the book, so that only the heading would show through the 'window' cut in the vellum.

A few words of the text can be read on the verso of the leaf, amongst which words such as 'Epactam aureo numero' are visible. This means that the text comes from the prefatory matter of a Roman missal printed after the reform of the calendar in 1582, in which the Epact is an essential part of determining the date of Easter. One of the cut-out windows on the verso would have contained the secition heading 'De Epactis, et Noviluniis'.

When the use of this frisket fragment ended, the sheet of vellum was cut up a second time. This piece was possibly recovered from a copy of the three-volume Greek and Latin Bible printed by Nicolas Buon in Paris in 1628.