The Matlab scatter plot that the concept started with. Ive forgotten exactly how I built it, but I believe it is a couple different Gaussian samples superimposed, each with random sizes of a different mean.
A couple highlights from the sickening range of designs we went through in converging to the final version. Not much of the scatter plot survived, I spent a lot of time drawing extra dots by hand. Of course in the end the postcards wound up cropped totally differently by the printer...