In the 3D effects, the lenticular plastic allows each eye to see a slightly different representation of the same scene. The brain integrates both images and thus creates a three-dimensional illusion in the viewer without the need for special glasses. The flip, animation and 3D effects can be mixed in order to maximize the visual impact of the images.
The effect is simulated in these online demonstrations:
/resources/site1/General/3d poster catering.swf
/resources/site1/General/hockey 3d.swf