what am I seeing here?

[Barb T]

For most cloths there is a difference in the warp and the weft, with the warp being the stronger, so for most patterns for 'normal' clothing the pieces are cut out along the long axis of the cloth. When worn the garments have the strong threads vertically on the body.

Actually, I don't think this is true. Clothing is laid out parallel to the warp (the "straight grain") of the fabric not because the threads are stronger but because the warp direction is less stretchy than the weft direction. When on the loom, the warp is under tension, and each thread is quite straight. The weft threads are not under tension and, at the fine scale, go up and down over the warp threads. This means that, if you pull the fabric parallel to the weft, it has some "give" as you stretch out the weft threads that have a slightly up and down path over the warp threads. Because you don't want your pants to give lengthwise, you lay out the pattern pieces in the warp direction. It's not strength - it's a matter of "give".

As a weaver, you can easily lay out a twill as a right twill or a left twill. Just depends on how you thread the heddles. And, if I'm remembering right, the same threading will give the opposite twill on a rising shed loom as on a sinking shed loom. And you can choose to weave with the top side of the fabric up or down (although many hand weavers weave with the top side up so that any mistakes are immediately obvious). I have no idea how these factors combine in the new rapier looms at Lochcarron. But I'm willing to bet that the changeover made a difference in one of these factors (top side, rising or sinking shed, or threading). It's entirely possible that all of the factors were constrained and they had no choice but to produce a tartan with a different good side than is traditional, although I find that hard to believe.

[ThreadBbdr]

*snip*

As a weaver, you can easily lay out a twill as a right twill or a left twill. Just depends on how you thread the heddles. And, if I'm remembering right, the same threading will give the opposite twill on a rising shed loom as on a sinking shed loom. And you can choose to weave with the top side of the fabric up or down (although many hand weavers weave with the top side up so that any mistakes are immediately obvious). *snip*

For a straight twill (like our tartans), you set up the heddles as 1,2,3.4. How you lift them will determine if the "line" runs right or left. You lift two treadles at a time. If you do 1/3, then 2/4 you get plain weave. 1/2, 2/3, 3/4, 4/1 should create a twill that moves from the weaver's lower left to upper right on a rising shed loom. You can do zigzags and birdseyes, too.

Anybody want a picture essay on this? I'd be glad to warp up a gamp (sample) and do a little tutorial.