The Paper Project is dedicated to exploring one of the earliest technologies and art forms, paper making. Within its pages, there is an article about how 3D glasses works. it is very interesting if you want to understand how the new 3D movies are made, or how the 3D images are taken, and why 3d glasses have a red and a blue lens. You can read the complete article here. Here is also a guide to make your own 3D-glasses.