The cover of Black Sabbath's new '13' album heralds the band's return to action with a distinctive image of the titular numbers burning against the night sky -- and now, thanks to the design firm behind the picture, you can see how it all came together.

The gig was handled by the U.K. firm Zip Design, whose website explains, "For the godfathers of heavy metal the concept for '13' came from a pagan influence of a burning wicker effigy. The setting for this is based in the British countryside at dusk to really set the scene and stamp the band’s roots into the artwork."

To capture that vibe, Zip commissioned photographer Jonathan Knowles for the shoot, which took place in Buckinghamshire during the dead of winter and was created using giant wicker constructions that "could be seen for miles across the frozen landscape" after they were lit. You can get a behind-the-scenes look at the process in Zip's making-of video, which we've embedded above. It's a short clip -- just over 90 seconds -- but watching it will get you a minute and a half closer to June 11, when '13' arrives in stores.