Since this subject has come up a couple of times, the scientist in me wanted to test the flammability of certain materials commonly used to make kilts ... and the kilt-geek in me decided to share the results of this impromptu little test with all of you.

My one brother and I took six samples, applied an ignition source in turn, and saw how easily the flames were extinguished.
The test materials:
  • wool sock (tightly shrunk weave) with poly-wool top
  • wool sock (loose/regular weave - unshrunk)
  • wool - Marton Mills 13 oz
  • poly-viscose - Marton Mills 11 oz
  • cotton duc 7 oz
  • three woven strands from a light wool blanket
The video:


You'll notice the wool, even the tartan scrap, stops burning when the torch is removed. The heavier wool in the socks was discolored, but the ash rubbed right off.
The P/V keeps burning/melting, but can be blown out.
The cotton ... And I made two kilts out if that stuff ...

Oh, and the discoloration of the American Heritage was interesting:

Blue to green and white to orange on the unburnt side. Not a method I would recommend for altering your tartans, but pretty cool results.