Known from two silhouettes. One, of a mother and her child, is signed and bears a trade label which indicates that Foster worked in Queen Street, Portsmouth. The sitters' costume suggests that the silhouette was taken in c. 1855.
Both the surviving profiles were full-length pieces, in which the figures of the sitters were pasted to the background.
Fosters work is conspicuous for the high proportion of Chinese white, and for the sharp colouring used on the dress of the sitters. In the illustrated example, the mother's clothing is painted in body colour, in a vivid shade of Prussian blue; she holds a lavender-coloured book. Her daughter wears a dress and cape boldly if clumsily painted in shades of maroon body colour. Both sitters' hair is painted in gold. The only part of the picture not painted in heavy body colour (which was no doubt used to conceal the black paper) is the posy held by the girl; this is fairly well painted. A slight wash base covers the base of the card to which the figures are pasted. The other silhouette which has been seen was conspicuous for the use of strong yellows. It was in a plain giltwood frame.
The artist appears to have signed his work, as well as using a printed trade label. His signature is simply ‘Foster’, inscribed within an oval; marked cross strokes emphasize each line of the F. The text of the trade label is as follows:
J. FOSTER
SILHOUETTE ARTIST,
QUEEN STREET,
PORTSMOUTH.
Portraits taken from 1s. to 5s.
Time of Sitting 4 minutes.
Ills. 408, 409