No idea about its origins, but I have two printings of the TSR boardgame "4th Dimension":  one of them has a nice heavy board, the other has a board that's basically laminated cardboard, although it's a smaller size (8.5"x11").  It's possible that TSR did it (mine doesn't have that lamination bubble, but that could simply be aging at work).

patweb wrote:It is from the D&D cartoon series.

*slaps ya with a wet trout*

I don't recall seeing one before and I've been collecting D&D cartoon stuff for a while.  I'd be interested in buying it, breach, if you're interesting in selling.

I seem to remember them handing them out at Gen Con when they were launching the series. They had a booth (maybe in the art display room - a little vague on that point) and TSR was giving away freebies to promote the show. I remember buttons and other stuff. There were smaller size posters and the like, too. It has been a very long time. I wasn't terribly interested by the show so I pretty much ignored the whole thing when I discovered how juvenile the program was.

But anyway. I am pretty sure the origins of this poster are directly related to that promotional event at Gen Con. The fact that there is no writing on the poster supports my recollection. I think I remember seeing other posters (small) that featured the characters with no text, too. At the time I thought it was weird...