Portrait of Willem van Loon,. Michael van Mierevelt, 1612

Michiel Janszoon van Miereveld (born May 1, 1567, Delft - June 27, 1641, ibid.) is a Dutch portrait painter.
The portrait of the founder of the Van Loon clan was placed by the owner for vacuum processing, so the entire surface of the painting turned white like it was covered with a layer of white bloom. It was almost impossible to distinguish the details of the image. The portrait seemed to be ruined.
The research showed that only the varnish was damaged. The damaged layers were removed,the transparency of the top varnish restored, and the painting sparkled with the bright colors of 17th century paints.