A 3-D viewer is created by folding paper such as card stock in a predetermined manner. A first section of the view carries a pair of 3-D lenses and a second section, which is held normal to the plane of the first section when the viewer is in use, has a longitudinal extent substantially equal to the focal length of the lenses. In a first embodiment, a third section is foldably connected to the second section, carries at least one 3-D scene, and is held generally paralle to the first section when the scenes are viewed. Other embodiments add additional sections which are foldably secured to the second or third section, a card holding member and pocket members for holding additonal 3-D scenes. Another embodiment includes slotted card members that are releasably attachable to a card holder member. A lens structure also protects the lens from abrasion and holds the lens in position so that the viewer can be mailed without being damaged.