Segesser I and II were painted on hides, likely bison, that had been tanned to make them supple, pumiced so that the grain was no longer visible, and sewn together to form a large canvas. The hides do not exhibit any distinctive ground or gesso layer under the paint.
Some scholars believe that the Segesser Hide Paintings were created in New Mexico, where imported canvas was rare and processed hides were used for a variety of purposes, including paintings on hide, or reposteros, that were exported to Mexico.