After a brief period working at the
type foundry Stevens Shanks, one of the last remaining in London, Mosley wrote many articles and books on the history of printing. Some of his best-known articles are 'English Vernacular', on British signpainting and lettering traditions from the eighteenth to the twentieth century, 'The Nymph and the Grot', on the early development of
sans-serif letters before they became adopted by printers, which was later republished as a book, and 'Trajan Revived', on the
Roman-style lettering revivals of the sixteenth and twentieth centuries. He collaborated with historians on other projects, including a printed edition of the decorated alphabets of
Louis Pouchée's type foundry, a study of the early printing of works by
David Hume and on the forgeries of
Harry Buxton Forman and
Thomas James Wise. He was a specialist on the career of
Vincent Figgins, an early nineteenth century typefounder, who founded the type foundry that later became part of Stevens Shanks. The St Bride Library, off
Fleet Street in the
City of London, was set up as a technical library to give
trade education to printers at a time when the area was a
centre of book and newspaper printing and publishing. From his experience working at Stevens Shanks, Mosley felt that they did not appreciate the value of the historic materials they owned, dating back to the beginning of the nineteenth century, He also advised on designing fonts based on historic typefaces and lettering, and was cited as an influence by font designers such as
Paul Barnes. After retirement from St. Bride Mosley continued to write, research and lecture. He also advised on historically appropriate lettering for
Bellerby & Co,
Tate Britain and
HMS Victory. Mosley was influential on younger designers through giving lectures on the history of letterforms as a guest lecturer at the
University of Reading and the
Rare Book School. His lectures for Reading in 2020-1 were recorded and, following his death, the University of Reading and his estate agreed to make them available publicly. File:St Bride Library 20130324 095.jpg|St Bride Library in the City of London, where Mosley was librarian File:Tate Britain (6 August 2023) 68 (cropped).jpg|alt=Tate Britain gallery|Mosley advised on historically appropriate lettering for
Tate Britain art gallery,
HMS Victory and
Bellerby & Co. ==References==