Wednesday, March 21, 2018

Biased, in the wrong direction

For a number of years now, I've paid fairly close attention to grain line in woven fabrics, much more so than when I first started sewing. It's interesting to me that cross-wise grain is different (and more stretchy) than length-wise grain. Today I had a tiny ah-ha moment when I realized that bias actually has two very different directions.

I began to consider this as I wore and enjoyed my most recent Chateau jacket, constructed from a thrifted bedspread. Although each front piece was cut on the same length-wise grain line, the neckline twisted in two different directions. Now that I look back I can see the twisting beginning right after I finished it.


You can just barely see the torque. The left side of the picture shows the corner turning under and the right side shows the corner turning out. Over time it became more pronounced and so it bugged me more. No amount of pressing and steam-setting eliminated the torque.




The neck edge is of course finished with bias binding. So I wondered - was it the bias-binding that was causing the torque? Of course the answer is yes. I tried to draw a picture to help understand how the bias created asymmetry in the front closure. Bias loves to twist and this is how I visualize it twisting in the original neckline.



So I recut the bias-binding. This time I put a seam in the center back of the bias binding. This allowed me to flip one bias piece to mirror the other in terms of the way it wants to twist.


Voila! Mystery solved.

Just for fun, I added a knot at each corner.
I am so easily entertained.



18 comments:

  1. Well who would have though! Thanks so much for posting this - it's super useful to know (and I love those little knots in the bias at each corner).

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  2. Brilliant! And the jacket looks great.

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  3. Great to have this information. Thanks for posting.

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  4. This is such a helpful tip and makes so much sense once you figure it out. I think about these kinds of sewing (and knitting) problems at night before I fall asleep. Thanks for sharing!

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  5. Great story! The jacket is so beautiful, lovely stitches, I'm glad you saved it. Bias on woven fabric really is a lurking beastie!

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  6. Now, aren’t you clever! And so early in the morning (for me) for this lesson😊

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  7. You ARE a cheap date, lol. Glad to see that you were able to work out how to solve the problem.

    I'd have just anchored the wayward flap with a brooch.

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  8. Genius! As a weaver, it makes sense that the weft direction (width) is more stretchy because the weft yarns aren’t under the same extreme tension as the warp (length) on the loom. I wouldn’t have thought the difference would be quite so dramatic in a fine woven fabric though. Great save. Might be weird but I kind of like the folded asymmetrical version too!

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  9. So fascinating and the effect is quite dramatic. I am going to keep thinking about this, wondering where else this type of relationship occurs in sewing. Kind of reminds me how 5+3 is the same as 3+5, but 5-3 is not the same as 3-5. The operation matters.

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  10. So smart you are! I'm sure I would never have thought of that as being the issue! Thanks for sharing. An by the way, the jacket is beautiful.

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  11. incredible! Once I started reading I said to myself...of course! I love the jacket and the new bias binding is perfect.

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  12. clever for working this out. I adore your new jacket and so glad you solved the problem. And made me aware of it!

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  13. Apparently there were looms in Germany prior to ww1 that could achieve equal tension in the warp and weft. But they were destroyed by the end of the war. So our woven fabric technology is ahundred years post its peak. Sobering thought.

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  14. Splendid work, what type of yarn used, where to buy this yards from?

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