As with other large size paper, six sheets are meant to be viewed
from a distance. As such, the artwork is usually coarser looking and lacks
the clarity and crispness of the smaller paper.
In the US, 6 sheets were a very common size and utilizes until the
mid 1980s. See the US article on 6
Sheet
In the UK, it's a different story; what we call a 6 sheet, they call
a 12 sheet. For more information on the British
6 Sheet, go to our British site.