Here's a great video clip (~17min) of Yoshiko and Kim Schuefftan* discussing, identifying and showing examples of different boro. There's a lot of great information to learn here. It's also fun to watch Yoshiko and Kim banter about with one another.
*Kim, who has been living in Japan for 40+ years, has had a long career as editor of some of the most monumental books on Japanese culture, including Yoshiko's seminal first book on shibori (yes, they've been friends for over 30 years).
Click here for video clip
You can see the full segment and learn other great information on shibori and textiles on the DVD, "Arimatsu Narumi Shibori" ($34.95, shipping included) available here.