An exceptional price of £25,200 was achieved for a print by the St Ives artist Peter Lanyon at Bonhams' Modern Prints sale (25 May).
The untitled work dates from 1949 and had been expected to make between £2,000-3,000. This unique piece shows Lanyon at his most experimental using pen, ink and gouache over a traced slate monotype printed in dark blue.
The print's dominant image of a horse links it to the artist's 1946 painting "Yellow Runner" and the large lino-cuts "The Returned Seaman" of 1946 (now in Tate Britain) and "Red Horse, Red Boat" of 1951.
Bonhams print specialist Tabitha Philpott-Kent said: "This was an exceptional price for an exceptional piece. It's a very strong image featuring Lanyon's trademark horses and boats."
Other highlights included £9,000 for a folio of screen prints by Patrick Heron (£3,000-5,000) and £5,520 for a Ben Nicholson Abstract Composition (£1,500-2,000).