Louis Osman (1914-1996) is best known as one of the leading post-war silversmiths and goldsmiths. During the 1930s he trained as an architect at the Bartlett School of Architecture and attended the Slade School of Art. He began his career as an architect in the office of Sir Albert Richardson where he worked extensively on new builds and restoration work. Osman moved from designing buildings to designing metalwork with ease, while acknowledging it was unusual. He wrote, 'In the past, people didn't mind if they made jewels or cathedrals; now, most architects would feel very let down if they had to make their wife a button.' He designed ecclesiastical plate and furnishings for Westminster Abbey, and Lincoln, Ely, Exeter and Lichfield cathedrals. Perhaps his best known work of goldsmithing was the crown which he designed and made for the 1969 investiture of Charles, Prince of Wales.

This design for a ring in the form of two bats holding a ruby was for a private commission for the collector Clare Lloyd-Jacob. Not being fond of rubies the design for Lloyd-Jacob was never realised. Along with E.492-2020 the two drawings show the progression of the design from a detailed, anatomically correct sketch of a bat with an outline of the possible form of the ring to the finished presentation drawing.