http://tags.library.upenn.edu/tag/PDF+3d_pdf PennTags Feed for /tag/PDF+3d_pdf PennTags Feed http://tags.library.upenn.edu/makerecord/url/11415 http://tags.library.upenn.edu/makerecord/url/11415 What is a 3D PDF? MAKE shows you! 3D PDF of Spud Gun <br /> Here's a quick screencast to show what a 3D PDF is