The volumes in this series contain Oppé's thoughts, opinions & philosphical musings on some or all of the following:
-life in general
-nature and travel
-everyday life, including family and health concerns, as well as major life events
-significant world events and politics, in particular, the first and second world wars
-the nature of art
-the study and practise of art history
-art historians (as individuals, or their work)
-specific artists or works of art
-collections and exhibitions
-the purchase of works of art, & other collectors
-the process of research and writing
-other forms of art, mostly literature
Some of the volumes were given a specific title by Oppé. Where this is the case, the information has been included in the catalogue record for each volume.
The content of the volumes is mostly presented as a series of chronological diary entries, but they may also contain research notes, financial workings (often in the back pages), sketches (depictions of art works or architecture), names and addresses, and bibliographical references.
Volumes APO/8/2/37-47 were written in the period preceding Oppé's first monograph on Raphael (see also: APO/1/17) and thus contain a mixture of research and musings on the artist, in addition to the standard content as noted above.
Much of the content of volumes APO/8/2/79-83 is devoted to the long article Oppé wrote for G.M. Young's 1934 publication, Early Victorian England (see also: APO/2/6).
The series includes a group of volumes that Oppé titled X1, X2 etc. (see: APO/8/2/87-APO/8/2/97) & in which he experimented with a different format. Thse volumes contain short numbered paragraphs, with each volume typically containing c 70-90 such entries. Most of these volumes have been fully transcribed, and they are some of the most candid in terms of content, containing extensive references to Oppé's private life and relationships. Within these volumes, Oppé also devotes a great deal of space to Chinese art, drawing extensive comparisons with European art. Despite Oppé's new number sequence continuing beyond APO/8/2/97, the volumes revert to the original format for subsequent books.
As the content of the black books is so rich, it has been impossible to list every subject discussed within each volume. Instead, standard catalogue entries reference significant discussion about
-works of art
They also detail whether Oppé was travelling when writing the notebook.
Some artists are frequently mentioned throughout the volumes, but never discussed at length. In the early volumes, Leonardo da Vinci is often referenced as a point of comparison in relation to other different artists. Likewise, there are several British artists - in particular, William Pars, William Taverner, Peter de Wint, David Cox, Samuel Palmer, Richard Wilson, Thomas Gainsborough and William Blake - who are regularly mentioned in passing, but, rarely discussed at length.