The object of a poster is to arrest the eye of a viewer and convey information. Creating a poster with three-dimensional effects can produce startling reactions from a viewer, prompting a double-take as his mind realizes it is perceiving something unusual. Large images rising out of a poster and other images with more subtle drop shadows create a surprising effect of both depth and projection.
Begin the project with a large white poster board, either foam or cardboard, as your canvas. Choose a size according to your need. Lightly sketch with pencil onto the poster board the projected placement of your elements.
Trim out photo elements, eliminating all background imaging, either in Photoshop prior to printing or by carefully excising the image with scissors.
Paste at least two or more images onto heavy construction paper. Trim them out carefully. On the back of these images paste large foam squares, 1/2-inch thick foam on the first image and 1/4-inch thick foam on the second image. This effect can be applied to a variety of images at different depths, but keep in mind that larger images projecting farther out of the poster imply that they are closer to the viewer or larger in scope.
Apply paste to the foam on the back of the first image, and adhere this to the top of the poster board, with 1 inch of the image projecting above the poster board and 1 inch projecting outside the poster board on the left side. Affix the second image in the same manner at the bottom-right side of the poster board.
Add in a text portion of the poster, in very large letters, making certain that the text does not overwhelm or overshadow the images. Center the words, one below the other, large and placed appropriately for the overall image of the poster.
Paste the text box with all the information you wish to convey on the lower-left side of the poster board. The large 3D images will capture the eye of someone standing far away from the poster and draw the viewer closer to read your information.
Paste in other photographic objects such as smaller objects, or slightly blurred objects to imply greater distance, that sink far back into the poster. Be certain to add a drop shadow in Photoshop, so that some of these images stand out from the background, providing a 3D illusion even among the "pop-out" pictures.
Build a poster by creating the background first, with vivid blue sky and startling green grass, and then build in layers on top of this foundation. If you have access to a large-media printer and Photoshop, this entire poster can be built first in Photoshop, printed and then all foam "pop-outs" can be added over the original poster.
Be creative, and have fun. An example of this finished poster could be a giant balloon rising up out of the poster (on a much taller block of foam) with a photographer at the bottom of the image aiming up to take a photo of the rising balloon, with a distant crowd blurred into the depths of the poster. Cloudy text could float in the sky reading: "Above the rest."
When creating "virtual depth" by utilizing various layers of foam, do not confuse the implied depth perceptions by placing smaller, distant images onto taller blocks of foam, or the overall effect could be compromised.