The files in this series contain material on individual artists, collected and compiled by Millar throughout his career. They are primarily a visual resource, containing a large number of black and white photographs and images of paintings. They also include correspondence with owners, auction houses, academics, museums and galleries worldwide; research notes; journal articles; summary descriptions of paintings; conservation and accession reports; exhibition catalogues and pamphlets.
Millar labelled these files by artist surname. In the interest of clarity, the full name, known life span or period of activity (as stated in the Getty's Union List of Artist Names) has been added to the file title in the catalogue. For files on multiple artists this is recorded in the description to prevent lengthy and confusing titles.
For artists with multiple files Millar often included a descriptive suffix, e.g. 'Dahl: Female 3/4 length'. These descriptions are represented in inverted commas following the artist's full name and dates. There are a large volume of files concerning Van Dyck (89 files) and Lely (38 files) in particular, as well as Dahl (8), Dobson (7), Kneller (12) and Rubens (15).
Most files contain a number of images of works by each artist. The total number of images is listed in the 'extent' field. The file description does not include any additional information about individual images, but each item of non-image material (ie. correspondence, notes etc.) is listed in detail.
Many of the images in the files on Van Dyck are annotated on the back with roman numerals, e.g. 'IV 228'. These references correspond to image numbers in Millar's chapter of 'Van Dyck: A Complete Catalogue of the Paintings', published by Yale University Press and the Paul Mellon Centre in 2004. Much of the content of these files dates back to the 1950s, but it is likely a large volume of material in the Van Dyck files was collected and arranged during the research and writing of this book (1990s-2004). For a sequence of files concerning the book see ONM/6.
The research files were kept by Millar at his home before transferral to the Paul Mellon Centre in 2008. They were viewed by a number of researchers prior to cataloguing but have not been merged or re-arranged by Archivists, other than to alphabeticise the file order. The content of each file has been re-packaged into archival folders from the original aging slip files. It is clear in some cases that Millar intended to re-arrange or merge certain files at a later date, e.g. ONM/2/225, a file on Lely titled 'Miscellaneous Lelyesque therefore sort with Lely Studio'.
Alongside these artists research files, Millar created files relating to broader subjects, eras or themes in XVIth and XVIIth century art. As these files don't concern specific artists they have been catalogued in their own sequence - ONM/3, Research files on subjects.