These would make fun, beautiful, durable holders for 3 part cards and other card materials
http://www.wikihow.com/Make-a-Folder-out-of-Duct-Tape
http://www.instructables.com/id/duct-tape-school-folder/
http://www.instructables.com/id/Duct-Tape-Pocket-Folder/
http://monkeysee.com/duct-tape-school-folder-and-notebook/
http://www.sophie-world.com/crafts/duct-tape-folder-craft