I found an interesting site today called Graffiti Analysis that studies the unseen motion involved in creating a tag as opposed to just documenting the results. The original version of Graffiti Analysis, developed in 2004 as part of thesis research at Parsons in New York City and can be viewed here. The new version is done with custom software that records the motion data and archives it in a free database housed at 000000book.com in Graffiti Markup Language (GML) files, a new digital standard used by other popular graffiti applications such as Laser Tag and EyeWriter. Influential graffitis artist such as SEEN, TWIST, AMAZE, KETONE, JON ONE and KATSU have had their tags motion captured using the Graffiti Analysis software.
The custom software they use is Graffiti Analysis 2.0 that are playback and capture applications available for free in OSX, Windows and Linux as well as the open source code for both applications. You can also get both in one package with their iPhone application called Graffiti Analysis available through the iTunes Store for $1.99. The downloadable desktop applications require some handy work to build an acrylic capture stand that isn’t that hard to make but the iPhone application may be easier starting point for most people. The iPhone application records your tags with line thickness based on the speed you draw the tag and you can uploaded your tags to 000000book.com for free just like the applications. The resulting tags rendered in 3-D space with the ability to rotate the phone rotates the tag in 3-D and use multitouch to zoom in and out.