Working in a Detroit art studio in the 50's and 60's was an exciting time as things were booming. There was more than enough work for many artists. Commercial artists came from Chicago, Cleveland, St.Louis and even from New York to work in this lucrative market. For years I specialized in ink line art and the assignments could vary greatly as shown by the two examples below.
The art director specified that he wanted a thin line drawing with no variation or tones. This was drawn with a technical pen.
This thick line illustration was drawn using a bristle brush. I don't recall the ad agencies on these pieces but the one above was probably done for my travel agency client.
I did all types of line art, from detailed crosshatch drawings to bold brush renderings, mostly for the Detroit automotive companies, but there were many other clients at the Detroit ad agencies as well. I was also getting work from clients in Chicago and New York as well.