Art. Baseball cards
Art as collectible. Baseball cards as collectible.
Art signed. Baseball cards autographed.
Art as aesthetic object. Baseball card as aesthetic object.
The mark of the artist. The mark of a baseball player.
Paintings are indexed in catalogs. Baseball cards are indexed in catalogs.
Some baseball player autographs have wonderful aesthetic qualities. I went on eBay and purchased the autographs that looked most visually interesting. Then I went to the Art Institute of Chicago's modern wing and matched up the aesthetics of the autograph with modern paintings.