I remember seeing a how-to that you printed out your picture in stripes, one strip was one picture the next stripe was the alternate picture, and then back to the first picture and so on. then you folded the picture into a zig-zag and glued it on to a backing.

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ Folded picture
------------------------------------ Backing

The illusion was that when you looked at the picture as you entered the room it looked one way and as you left the room it looked another. The issue is that in the middle of the room you would see both in the stripped pattern. One way to fix this problem is to control the lighting on the picture. As the person get close to the center of the room turn the picture lighting off and then back on as they are almost ready to leave.

I would agree the lenticular ones are better though!

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- Brad

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Haunt at Red Clover
Parker, Colorado