This series consists primarily of personal and professional correspondence between Eric Gill and publishers, patrons, family members, friends and influential members of the London art world. The series includes Gill's letters to the editors of various newspapers and periodicals with his drafts, press clippings of the published letters, press clippings of responses, and related correspondence. These files are arranged alphabetically under the publication's name. A substantial portion of the correspondence series also consists of condolence letters and telegrams sent to Mrs. Mary Gill after Eric Gill's death in November, 1940. Also included are nine manuscript shorthand notebooks in Gill's secretary's hand of letters dictated by Gill from 1936-1939, a Gill letterbook, a bound collection of Gill's rough drafts of letters written July-November, 1940 and Gill's Letters from Jerusalem. These items are arranged alphabetically by title at the end of the correspondence.

Correspondence received by Eric and/or Mary Gill is filed alphabetically under the correspondent's name; correspondence sent by either of the Gills is filed alphabetically under the recipient's name. Items within each file are organized chronologically. The alphabetical arrangement imposed by the Clark was retained during processing. Some reorganization was implemented, however: correspondence previously separated into groups of uncataloged and cataloged material was interfiled to facilitate easier subject access. Similarly, correspondence previously divided by incoming letters to the Gills (alphabetically arranged by correspondent, then date) and incoming/outgoing letters to the Gill's (arranged chronologically) was interfiled alphabetically as one unit.

Correspondence pertaining to a specific manuscript work is filed under that work in Series 2. Professional papers, subseries A. Manuscripts.