The del Perugino Book of Hours is entirely written in dark brown ink in a well-made classical style ascribed to the calligrapher Pierantonio Sallando. The  illustrated letters in the bottom margin of folios 48r and 58v are typical of his writing, while the titles are in gold.
Originally from Reggio Emilia, Sallando was a teacher of grammar and calligraphy at the University of Bologna and was also the proprietor of a workshop specialized in the creation of this type of manuscript, as confirmed by the numerous examples of his work that have been handed down to us.