Regarding the question in last Friday’s poll -Which is the more stable grain? -the answer is the cross-wise grain. 54% of respondents said it was the lengthwise grain. Pasting in my response from the forum:
I think people have the wrong idea about grain. For some obscure reason, people have it cemented in their heads, that the length of grain is the more stable grain. This is absurd. The straight of grain is under the most pressure, it’s stretched. Accordingly, it also shrinks the most. In reality, it is the cross grain that is the more stable grain. The reason we cut on the straight of grain is for allocation. As the rationalization for which has been long forgotten, the practice has been elevated to a “must” rule. [“It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so.” -Twain]. Silly silly. If anything, cutting on the straight of grain, allows the cross grain to do its work of stabilizing a garment from side to side -the greatest stressor.
For those who inquired about knits, these goods are knitted and as such, only have one “grain” (assuming it could be described in these terms). In any event, a static relationship was not implied as a condition of stability. Ex: knits necessarily include recovery, a definite component of stability.
Kathleen, I remember your mentioning that the cross grain was more stable a while ago. I just made a satin party dress and did it on the lengthwise grain because of allocation and it looked better that way. :-)
I always cut the washed/distressed dupionni silk I use to make my custom men’s shirts on the cross grain. Not only do I like the way it looks (the slubs running vertically), the drape is more “fluid” and, in my experience, it is easier to sew. Not to mention that the shirts hold their shape beautifully through subsequent washing!
~Pam
I think people misinterpret tensile strength as stability. I also find people extrapolate that increased fabric thickness or weight increases tensile strength – again it not always the case.
I was led to believe the cross-wise grain had more stretch (= less table) because the weft threads curve under and over the lengthwise warp. Also, weft threads tend to be weaker than warp threads, though I don’t know if this affects stability.
It does make sense that the warp, when relieved from the loom’s tension, will shrink up, but isn’t that a once-only thing?
I guess I see points for both answers.