A wing altar by Lucas Cranach the Elder dating from 1539 from the St. Wolfgang church in Schneeberg was restored in 1969. To do the necessary touching-up over a dammar varnish (1:6 in rectified turpentine oil) water-diluted imported acrylic colors were applied. When the results were checked 14 years later, a noticeable darkening of the acrylic colors had occurred and thus made the repairs quite visible. There is not certainty as to the causes.