In 2015 researchers discovered a signature on a painting by Claude Monet. A painting titled “A Haystack in the Evening Sun” from 189-92, appeared to be unsigned.

Researchers at Finland’s University of Jyväskylä took images of the painting with a hyperspectral camera, also known as a XRF device. The images used taken were on the infrared or near-infrared spectrum, exposing imagery not visible to the naked eye. The scientific testing revealed a hidden signature found under a surface layer of paint. Finding the signature helped to confirm the authenticity of the painting, which was previously somewhat doubted by scholars.

Find out now if you have an authentic Claude Monet painting or drawing: