Chapman made frames for Shannon and there is little reason to doubt the company made this example. The frame fits a group in the collection making use of gilding direct to the oak. It represents exactly the frames associated with the artist.1
Note
1 See Fig 79, p. 76 in Jacob Simon, The Art of the Picture Frame, National Portrait Gallery, London, 1996. The self portrait, Charles Haslewood Shannon, 1897, NPG 3107 is framed in this manner, also the portrait Charles de Sousy Ricketts, by Shannon, 1898, NPG 3106.
The frame is made from three pieces of oak timber. The major section is the shaped profile, a simple low relief of ogee, cavetto, flats and rounds. The working edge is made up by the addition of a strip of timber and the sight edge is established with an additional flat. The structure uses mitred corners that have been braced on the reverse with blocks.
The frame appears to be in original condition.