As I said, the billboard thing was interesting, as when up close and personal with some, all discernible image was lost, replaced by a somewhat abstract design of dots.
Some of these made great wallpaper, though I'm still occasionally haunted by the large dotted image of Jon "Bowzer" Bauman, and Sha Na Na staring down at me from the wall of the attic loft which was my bedroom in the mid '70's