Making "Stereogram"
So I decided that the best thing to do was to make an extremely simple stereogram. I downloaded a shareware package called Stereogram Explorer and began experimenting. It turns out that there is a real art to designing an effective sterogram – an art that I never quite learned. One of the biggest challenges is that, due primarily to pixel size, stereograms that look good on the screen often don't print well, and vice versa.
It probably took me a week of attempts before I came up with the stereogram I eventually sent out.
Some people never see the effect. In this case, the stereogram is the words "HAPPY NEW YEAR".
If you liked this, or even if you didn't, please let me know.