If you have any braaaaaiiins you'll shuffle immediately to Leigh Gallagher's fan-sodding-tastic blog to see how he put together the striking cover of Prog 1836.
It's a frikking work of art, such a strong image, I love it! On his blog, Leigh shows you his initial (not as good!) idea, sketches, pencils, inks... the lot!
See it here!