Collectors distinguish between art (of all forms) reproduced on postcards, and art created for postcards by postcard artists.
Introducing Postcard Artist Cobb Shinn (1887-1951).http://hoosiercartoonists.blogspot....f-month.html
... artist biohttps://muscleheaded.wordpress.com/...-cobb-shinn/
... an entertaining blog post on an entertaining bloghttp://www.mtfca.com/
... I found Mr Shinn's (mostly comic) Ford Model 'T' postcards by googling 'mtfca Cobb Shinn' more easily than by using their forum search engine, but that's me
My card, one of a series, can be found for sale, here & there.