Ad comp layouts were done much larger than storyboards and rendered tighter with more detail.
This was a rendering for a magazine ad and was about 11 x 14" in size. I don't remember the ad agency or the art director, but it was for one of my New York clients and was one of a series of ads.
Above is an actual size section of the rendering which gives you an idea of the detail. I used a Pilot Razor Point pen for my basic drawing, then rendered it with markers on high quality layout paper. When I received assignments like this there were usually six or more in a series and they often came in on a Friday with a Monday AM deadline. After the year 2000 I delivered everything over the internet.