Alan Grossman, a New York lawyer, is fond of his gleaming new iPhone 6 Plus. Seated at his favorite cafe on a recent morning, he conjures up a Google map of Memphis.

Then, he pulls from his back pocket an illustrated map of Memphis printed on thick color paper. Unfolding it to its full, detailed, 18- by-27-inch grandeur, he places it next to the digital map.

“Here...