Peter Blake valuation

Blake is one of the most heavily editioned artists working in Britain, and the print output runs from small, early, genuinely scarce editions to very large recent screenprint and giclee editions published in the hundreds. The two are not comparable, and separating them is the whole of a valuation: publisher, date, edition size, and whether the sheet is signed and numbered in pencil. Paintings, collages and the boxed assemblages are unique and sit far above the prints. Condition of paper, fading and light damage are the usual issues.

Sixty years of printmaking through a long list of publishers means the same image frequently exists in more than one edition: different sizes, different colourways, different papers, editions running from tiny to very large, and later re-editions of earlier images. A photograph of the image alone often cannot tell one from another. What does is the pencil inscription, the edition size, the publisher's details and the sheet dimensions before any trimming.

The other thing that arrives under this name is not art at all in the market's sense. Signed Sgt. Pepper sleeves, signed books and signed posters are memorabilia, sold in a different room to different buyers on the strength of the signature rather than the object. They can be worth having. They are not editions, they are not valued like editions, and the first useful step is establishing which of the two you are holding.

He was first named with British Pop in the Young Contemporaries exhibition of 1961, alongside David Hockney and R. B. Kitaj, and won the junior John Moores prize that year with Self Portrait with Badges. Ken Russell's film Pop Goes the Easel brought him to television in 1962. Robert Fraser represented him from 1963 and gave him his first solo show in 1965, and from 1969 Leslie Waddington's gallery took over. On the Balcony, of 1955 to 1957, looks like a collage and is painted throughout.

Babe Rainbow, a screenprint on tinplate published by Dodo Editions in 1968, was made in an edition of 10,000 and sold cheaply, which is why it turns up so often. Besides Sgt. Pepper, which won a Grammy, he designed sleeves for the Band Aid single, Paul Weller's Stanley Road, The Who's Face Dances and, 38 years later, WHO, as well as Oasis's Stop the Clocks and the 2012 Brit Award statuette. The Tate gave him a retrospective in 1983, and Tate Liverpool another in 2007.