Making soft cup bras is actually quite easy. Once you know what kind of elastic to use for each part, how to attach them and in what order you'll be able to whip up a bra in just a few hours.
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HOW TO attach lingerie (knicker) elastic
HOW TO attach fold over elastic
...and If you're making the LITTLE 'GIRLS' TRIANGLE BRA you'll also need to know HOW TO attach under-bust elastic.
1. For the LITTLE GIRLS TRIANGLE BRA you'll need a 15mm (5/8")under-bust elastic x approx 90cm (35 1/2"). Under-bust elastic will have a textured and/or shiny front but will always have a soft and smooth surface on the back. The back is soft because it sits next to your skin.
Mark the center of you elastic with a pin.
2. If you're making the LITTLE 'GIRLS' TRIANGLE BRA you will have already attached the lingerie elastic to the inner and outer edges of each cup and then joined them together in the center.
Measure along the bottom of the cups and using the equation below calculate the length of the under-bust elastic
total length of edge x .8 = elastic length
3. Mark the elastic at the correct point on either side of the center front. Now pin the cups in place right sides together with the picot edge facing down.
4. With right sides together and with the wrong side of bra facing up, use a wide zig-zag stitch to attach the under-bust elastic to the cups. Stretch the elastic evenly to fit as you go; the cup fabric should not be stretched. It's also very important to ensure that your stitching is evenly spaced from the edge.
Once complete it should look like this on the wrong side,
and like this on the right side.
5. Now flip the elastic to the wrong side so the picot edge is now facing up and pin in place at each end and in the center.
6. Using a twin needle stitch in place. Stretch the elastic evenly to fit as you go; the cup fabric should not be stretched.
7. Once completed the wrong side will look like this, and the...
right side will look like this.