Thoughts on materials....

[Barb T]

I agree with Steve's analysis of kilt swing and just want to add a couple things. One of the main factors governing whether a kilt swings/swishes well is the length of the fell (that's the stitched part of the pleats). If the fell is too short relative to the overall length of the kilt (or if the pleats aren't stitched down at all), the pleats aren't controlled enough, and they don't swing back and forth as a nice unit as the person walks or dances. So the pleats look flippy instead of swingy. If the pleats are stitched down too far, the fell controls too much of the fabric and there isn't enough weight in the unstitched part of the pleats to give the momentum of the swing.

I suppose it also has something to do with periodicity of the driving force (walking or dancing). If you did a thought experiment about it you could imagine taking a lot of little rapid steps, and the kilt swing would be all discombobulated; ditto if you took really long, slow steps - you could imagine the kilt swinging back at exactly the wrong time for the second step to drive the swing. So, it's not beyond the realm of possibility that the length of the fell evolved empirically. Aaaaaaannnnyway, Steve the engineer can weigh in on that little notion!

Even with the bottom of the fell in the right place, the weight of the unstitched part IS important. The heavier weight of 16 oz tartan will swing better than 11 oz tartan in a kilt of the same size and yardage.

What I'm starting to grasp is that the movement is more a function of the pleating that the material weight- smaller pleating = better movement...

So, yes, the weight of the tartan driving the swish is the important thing, but weight is not correlated with pleat size. Pleat size is a function of the size of the sett. If I made a kilt for an average-size guy with 8 yards of Volcano tartan, I might get 20 pleats that are an inch across and about 5" deep, because the sett size is about 10 1/2". If I made a kilt for the same guy with 8 yards of tartan with a sett size of 7 1/2", I might get 27 pleats that are 3/4" across and 3 1/2" deep. Both kilts would have exactly the same amount of yardage in the back (i.e., the same weight), just divided into different numbers of pleats, and the swing will be pretty much the same.