New to all of this

[paul cobb]

At a trade show, I was examining a manufacturer’s products. He had pictures (maybe 10”x10”) of his company’s products. When I held them in my hands, I could see just the picture of the product. When I tilted them, I could see a multi-colored hologram of his company’s logo. He told me he made them by creating the following “sandwich” -
¼” clear Plexiglas
clear double-sided adhesive
diffraction film
clear double-sided adhesive
picture of the product. Before he pressed-on the picture, he stamped, using a rubber stamp, an image of his company’s logo using a gold (?) powder(?) or paint(?). My memory is a bit hazy here.

Is this possible? I know nothing about holograms, but I would like to incorporate something similar in our exhibits. I found a site - http://gratings.newport.com – but I am pretty much lost as to what type of grating to select.

Any help would be much appreciated,
Paul

[JohnFP]

Well, as far as I can figure, the grating is a transmission grating. Thus before placing the photo he stamped a highly reflective logo which would be just over the photo near the rear of the sandwich. So light comes in and you see mostly the photo but at just the right angle the "gold" reflects light back so you can see the light bouncing off the gold and hitting the grating causing a rainbow effect or at the correct angle the grating diffused the colors and they reflect off the gold and back out the front to your eyes. The only thing I am not sure of, as you did not mention it, is the logo visible when viewing the picture and no colors from the grating can be seen? Do you see the gold logo anyway even if not colorful with light?