Banksy

Banksy has worked anonymously since the 1990s, and the anonymity is structural rather than decorative — it shapes how the work is made, how it reaches the market, and how it has to be authenticated. The stencil technique that defines the early street work exists because a stencil can be cut in advance and put up in seconds. Since 2008 the artist's own body, Pest Control, has been the only authority that authenticates work for sale, which is why paperwork sits at the centre of every Banksy valuation.

Girl With Balloon began as a stencil on a London wall around 2002 and became the image most people picture first. The 2004 screenprint edition was printed and published by Pictures on Walls in London: 600 unsigned impressions, each numbered in pencil and carrying the publisher's blindstamp, alongside a signed edition of 150 and 88 signed artist's proofs across four colourways. The sheets are 70 × 50 cm, printed in black and red on wove paper.

At auction the trajectory has been unusually abrupt. For a decade the record stood at $1.87m, paid for Keep It Spotless at Sotheby's in New York in 2008. In October 2019 Devolved Parliament — the chimpanzees in the Commons — sold at Sotheby's in London for £9.9m, roughly five times its high estimate. Then the shredding: an original Girl With Balloon sold at Sotheby's in London on 5 October 2018 for just over £1m and began destroying itself in the frame as the hammer fell. Reoffered under the new title Love is in the Bin, the same work returned to Sotheby's on 14 October 2021 and sold for £18.6m — the artist's record, and eighteen times what the unshredded picture had made three years earlier.

Those figures belong to unique works, and they are why the print market is watched as closely as it is. They are not what a print is worth. What decides that is narrower and duller: whether an impression is signed or unsigned, which edition it belongs to, whether the Pest Control paperwork is present and matches the work, and how the sheet has been kept. These are works on paper — they fade on a sunlit wall, they crease, they get trimmed to fit a frame — and every one of those reads through to an estimate.