Handbills and postcards containing the poster image were also produced. In addition, beginning in the summer of 1967, tickets to these shows contained miniature poster images in varying color combinations for different days of the same run of shows. The Bill Graham numbered series is extremely well documented - a circumstance which is quite advantageous to collectors some thirty years after most of these posters were printed. The series is widely collected and rare items in the series are among the most sought after pieces in the world of rock posters. The two key reference works for this series are The Art of the Fillmore and The Art of Rock.
Counterfeits also exist for several of the poster images.
Consequently, those who collect Bill Graham Numbered series posters are well advised to seek out and learn the printing history of the posters in this series. Traditionally, poster collectors have considered the Family Dog numbered series to at least as important as the Bill Graham series. Chet Helms, whose name has become synonymous with the Family Dog, was central a figure in the Haight Ashbury hippie community and had his finger securely on the pulse of the times. It was through his foresight and diligence in spreading the word of the new ethic by distributing posters throughout the community that the psychedelic poster movement took form. It is this close association with the most positive elements of the times that has endeared the Family Dog posters to a whole generation of collectors.