A 500-year-old engraving by the Northern Renaissance master Albrecht Dürer that was rescued from a garbage dump is up for auction and could fetch up to $26,000.

As a boy, Mat Winter was fond of rummaging around the local dump in Kent, southeast England, and looking for antiques. According to Winter, one afternoon he found an old print and, liking the look of it, he took it home. It has been tucked away in a cupboard along with the rest of his salvaged antiques for more than a decade.

Earlier this year, on a whim, Winter sent the print to be assessed by Rare Book Auctions, an auction house in Staffordshire, in the West Midlands of England. After passing through the company’s parent branch, it arrived before the director, Jim Spencer. “When the vendor said it had been rescued from a tip, I didn’t expect much,” Spencer said via email. “I felt a shiver of excitement as soon as I looked upon this print…and I was straight on a train to the British Museum.”

Detail from Albrecht Dürer, Knight, Death and the Devil (1513). Courtesy: Rare Book Auctions.

Certain that the print was by Dürer, Spencer set up an appointment with the British Museum’s prints and drawings experts to determine if it was an early and therefore more valuable example. The print was promising. The paper’s texture was right for the period, Spencer said, and the “level of detail was breathtaking.”

By comparing the print with the three in the British Museum’s collection, Spencer was able to confirm the work was Knight, Death and the Devil (1513) and was one of Dürer’s three Meisterstiche, or master prints. The key detail that proved the case was an incredibly faint scratch across the head of the knight’s horse, a mistake that was accidentally traced across the copper plate before printing; it disappears only in later prints.

Detail from Albrecht Dürer, Knight, Death and the Devil (1513). Courtesy: Rare Book Auctions.

It’s believed the print comes from sometime in the middle of the plate’s life and was pasted down onto its current mount around 1900. An excellent, unmounted early print of Knight, Death and the Devil, Spencer said, can draw prices around £200,000 ($260,000).

“Dürer’s earlier, more Gothic woodcuts were revolutionary,” Spencer said, “but his copper engravings were even more amazing, awe-inspiring, almost superhuman – as this engraving shows.”

The online auction runs until September 18.