http://en.wikipedia.org/wiki/Wallpaper_group this covers every regular and semiregular tessellation that we can fold, I think. or all the possible orientations. I haven’t thought through all the ramifications of this, but I’m pretty sure that anything that we can fold fits one of these models. things get a little more complicated topologically since the paper isn’t really “flat”, and there’s more dimensions to the folding, but that’s rather beyond me.