Tuesday, December 11

Sewl Food: Bias

That darn McCalls 5466 dress did not work out in the end, but I didn't let it break me. I turned it into a learning experience. I spent the week/weekend learning why it didn't work and it turned out it was the fabric! The type of fabric I used was unknown to me (from Aunt's stash) but it closely resembles the "linen tweed" I saw recently in A Fabric Place. The problem that I didn't know from the beginning was that the loose weave was the reason I had a hard time from the get go with lining up the grain when I was cutting and the over-stretching with the zipper application.

I never thought about bias cutting before since I'd never done it. I just figured it was another way to line up a print. WRONG! I got in my books and on Google and found some useful info. Here is what I learned about bias:

"Fabric cut on the bias has much more elasticity than when it is cut on the straight grain. An angle of 45 degrees to the straight grain of the fabric is known as the true bias.

As the bias grain of a fabric stretches far more than the true or crosswise grain, great care must be taken when cutting out and seaming the sections.

If the fabric is distorted out of shape at either stage, the garment will not hang correctly. Garments cut on the bias will have a tendency to drop, or stretch. It is a good idea to allow a bias cut garment to hang on a suitable coat hanger for at least 24 hours before hemming it."
from Take Up Dressmaking by Sue Whiting

Here is more info from an awesome and thorough Threads article.

Widen seam allowances
Although bias cuts don't ravel, the fibers on cut edges relax and open up, so even 5/8 in. away from a cut edge isn't an accurate stitching line. To your adjusted pattern pieces, add 1-1/2-in.-wide seam allowances, in addition to the extra ease, on center, side, and shoulder seams. Use 5/8-in. seam allowances at the neck. Always mark stitching lines with thread, tracing paper, or chalk as soon as the fabric is cut, before removing the pattern pieces.

Remove excess stretch
To prevent bias-cut garments from continuing to stretch as they're worn, it helps to press each pattern section to remove some of the stretch before construction. Pressing simulates the effect of gravity and results in a more stable garment. This step is a lifesaver when working with silky, gauzy, or loosely woven fabrics.

After cutting the fabric and removing the pattern, press each piece firmly, gently, and evenly from top to bottom. Now repin the pattern onto the fabric, adjusting seamlines if the piece has grown smaller.

Sewing bias seams
The key to smooth vertical bias seams that won't pop when the garment is worn is to stretch them as you sew, using a 2.5- to 3-mm stitch. The seam will look rippled after stitching but will press out beautifully. You don't need to stretch as you sew shoulder seams because they're not cut on the true bias, and so don't stretch as much.

To assemble the garment, sew center seams first, then fit at the side seams by pinning along the stitching line, wrong sides together, and adjust to get the look you want. After the garment is fitted and sewn, trim seam allowances to 3/4 in. Since bias doesn't ravel, seam finishes are optional. I prefer a pinked edge; the serger can cause rippling and seam show-through.


So equipped with that info, I got busy on another version of the dress with a better fabric! Here is a preview.

look at that butter smooth zipper!!!
"...
not no Parkay, not no margarine, strickly butta baby, strickly butta"

5 comments:

flytie said...

yeah, the bias cut is its own thing. and don't you just *love* when a zipper comes out so smoothly? one of my happiest moments, ha ha! :-D

narcissaqtpie said...

true.dat.

cidell said...

Oh. Who knew? I love that tip on pressing the bias.

Lovely said...

Oh the things we learn!!

Carolyn (cmarie12) said...

I love that you didn't give up but kept pressing on!!! Can't wait to see your dress!