Here is a Tartan painting tutorial that I plan to try out. This is the pattern for the 79th:
ADDENDUM: Here is the tutorial provided in Greg's comment below of another way of doing tartans. It looks similar to the Cameron pattern with it's red stripes. I don't know if I can manage that thin lines though - the thinnest brush I have ever used is 00. Anything thinner would seem to have the paint dry on the brush before it can make it to the figure. Maybe it's because the brushes I've been using for the last five years were all bought when I was stationed in Korea and were about a $0.50 a piece. My wife bought them at a factory where they were made. She bought a lot of them, but I now only have about 10 left.