With its hand-written notes and stapled-on fragments of other prints in the margin, this piece is unique in that it bears traces of numerous inspections, manipulations, and direct interactions by both Ruscha and his master printmaker.

This primary market artwork is a Working Proof; it refers to a trial proof impression on which the artist makes corrections and revisions by hand to direct the master printmaker. It is printed while the matrix (any printing surface, such as a metal plate or a lithographic stone) is being developed. If retained, Working Proofs are generally inscribed (as opposed to being numbered), making them completely unique. They are hardly ever authenticated by the artist and are only signed if he or she feels like they are a desirable variation. They are often collected by museums and displayed as historical artifacts documenting the production process behind a particular edition.