From Wikipedia:
Zen and the Art of Motorcycle Maintenance: An Inquiry into Values is a book by Robert M. Pirsig first published in 1974. It is a work of fictionalized autobiography and is the first of Pirsig’s texts in which he explores his concept of Quality. […] Pirsig received 121 rejections before an editor finally accepted the book for publication – and he did so thinking it would never generate a profit. It was subsequently featured on best-seller lists for decades, with initial sales of at least 5 million copies worldwide.
Bantam’s paperback edition was first printed in 1974. One of the copies digitized by the Internet Archive mentions 39 printings through November 1989 – 26 by Bantam through November 1980, and subsequent ones in Bantam’s New Age imprint from October 1981. While the typographic cover design with all-caps Benguiat Montage was maintained throughout the years, the book came in various color variants.