EDINBURGH, Scotland (KFOR/Storyful) – Hidden from view for more than a century, a self-portrait of Vincent van Gogh has been discovered via x-ray on the back of his famous painting, Head of a Peasant Woman.

Officials with the National Galleries of Scotland say they found the portrait of Van Gogh wearing a hat while examining his Head of a Peasant Woman painting for damage ahead of an upcoming exhibition.

According to the National Galleries, in an effort to save money, Van Gogh would often reuse his canvases, turning them over to paint on the back, rather than use a second canvas. However, his self-portrait was covered in layers of glue and cardboard.

Museum curators are researching how to restore the portrait with very delicate preservation methods, without damaging the Head of a Peasant Woman.

“Moments like this are incredibly rare. We have discovered an unknown work by Vincent van Gogh, one of the most important and popular artists in the world. What an incredible gift for Scotland, and one that will forever be in the care of the National Galleries,” said Frances Fowle, senior curator of French art at the National Galleries of Scotland.