The Mudd Club series includes a large number of notebooks which contain planning and working notes. In particular are the annotated calendars spanning the years 1979 to 1983 which document the booking process for the nightclub and span the club's lifetime. Other notebooks created during the Mudd Club's operation include business notes, such as floor plans, diagrams, phone numbers, business cards, and other vendor information and coordination notes. This series contains a large number of photographic prints, negatives, and slides of parties and events at the Mudd Club, as well as slides and slide shows that were projected during events. Additional materials such as business plans and proposals, legal correspondence, check ledgers, and other financial records document the administrative side of the club's operation. There are also magazines, newspapers, and a limited run of the East Village Eye, which highlight the press coverage and publicity around the Mudd Club at the time. Promotional materials includes photographic and Xeroxed images, newspaper and magazine clippings, transparencies, and mockups and layouts of posters, newsletters, postcards, brochures, programs, invitations, or flyers. Membership cards, a guest book, a photo album, mailing lists and labels, and Rolodex contents document club attendees, vendors, and performers.

This series also includes handwritten notes, outlines, diary entries, and typescript manuscript drafts for Mass's unpublished memoir, as well as competitive analysis and manuscript submission packets to publishers; interview transcripts and correspondence with Tim Lawrence; and a copy of The Riddle of Dr. Mudd. There are also audiovisual materials, such as audiocassettes and film and sound reels.

The majority of materials in this series are in German. Materials documenting the operations of the Mudd Club Berlin in 1999 and the 2000s include financial and legal documents; floor plans; correspondence; business proposals; planning and working notes in notebooks, notepads, and calendars; business cards; mailing lists; press coverage; two company stamps; and promotional materials. There are also photographic negatives and prints documenting the condition of venue spaces, with a smaller extent of material documenting parties and events. Much of the financial and legal documents pertain to loans, contracts, building applications, zoning, and noise complaints, among other issues. Some of these subjects also come up in the planning and working notes of the series, which also include research materials, inventories, diagrams, and payment notes.

This series consists of notebooks, research files, correspondence, grant proposals and business plans which document Mass's restaurant planning, his work with Innovative Community Enterprises, and other nightclubs and businesses. The bulk of materials in Series III regard the planning of the restaurant at 77 Church Street that chef Bernard LeRoy and Mass began together, and notes include but are not limited to: diagrams, floor plans, photographic prints and negatives, catering schedules, calculations, budgets, equipment and supply notes, meeting notes, schedules, and recipes. Materials from Mass's time with Innovative Community Enterprises are primarily in electronic format, and include correspondence, reports, and meeting minutes.

This series consists of personal correspondence, research files and manuscript drafts on Haiti after the overthrow of President Jean-Claude Duvalier, a Boy Scouts merit badge sash, a 1956 senior high yearbook, and photographic prints, negatives, and slides. The photographic prints, negatives, and slides document Mass's own personal trips to places like Lourdes, France; Barcelona, Spain; Miami Beach, Florida; and Newton Falls, Ohio, as well as photographic subjects of street scenes and people.