Islamic artists often use texts in this way. I remember a beautiful stylized painting of a horse where the outline and detail were a poem describing the horse. Can't remember who was given the credit as artist (and it was a time ago) but glancing through some old art books I have found a few Persian rugs where text weaves through the design. Also remember Alice in Wonderland, the poem about the mouse? In the book, it is printed in the shape of a tail - always fascinated me as a child. I have forgotten the term for this but there definitely is one.