I know we have more than a few BATHORY fans in here, so maybe this will be of interest if you don't already know the story behind the "Under the Sign of the Black Mark" album cover...
It is not a painting. Yeah, sounds hard to believe huh?! The photo was taken at the Royal Swedish Opera House only seconds before Act II of the play "Carmen" commenced. The stage featured a rocky, mountainous set which was perfect as Quorthon wanted to recreate something with Francisco de Goya's "Witches' Sabbath" in mind. Four half naked girls were supposed to be in the photo but the photographer was unable to properly fit them in. The infamous Goat headed Beast was portrayed by Swedish body builder Leif Ehrnborg (bottom left photo), who wore a papier-manché goat head and loincloth, whilst swinging a gigantic ox-bone with decaying meat still on it! On the other hand he was shaking a rag of cats fur though it can barely be made out on the actual album cover.
Only four shots taken in total and in order to make The Beast more noticeable, the center piece of the shot had to be enlarged to such an extent that vast parts of the set had to be left out of the album cover. The photo on the top left is one of the unused ones from the session. Hard to believe yes, but this seems to be the story behind this classic album cover!
( I got most of my information from this excellent page, be sure to check it out for a much more in depth story:
http://www.bathory.nu/07_under_the_sign/07_underthesignoftheblackmark.htm )