Here's a simple tartan. Not much in the way of calculation in this case, just using a 1-row image for the pattern that I'm loading into two separate image-map nodes. I'm debating whether I should make another compound node that lets one specify a sequence of colors and thread counts. The problem is that because of how Poser nodes work, I'd have to put an arbitrary limit on the complexity.

-- I'm not mad at you, just Westphalian.