This is beautiful and highly impressive.
Graffiti Analysis is an extensive ongoing study in the motion of graffiti. Custom software designed for graffiti writers creates visualizations of the often unseen motion involved in the creation of a tag. Motion data is recorded, analyzed and archived in a free and open database, 000000book.com, where writers can share analytical representations of their hand styles.
Hit their site for more. http://graffitianalysis.com