Following on from the tutorial 'How to make a pair of briefs' is 'How to make a soft bra'. Using just a sewing machine and the same fabric as the briefs, the following is how I would put a bra together. The style is inspired from the 1950's with a high apex (where the strap meets the top of the bra). The size is a 34DD, I have chosen a bigger size to show you that this style can go up to a bigger size but will be fully lined for support. If you were making a smaller size then you wouldn't have to line it, but you could just use tape or ribbon over the seams to hide them. As this bra is being fully lined we are using the fabric to hide the seams.
An important factor when making a (soft) bra is that the outer part of your breast is the heaviest so this is the area which will require the most support. With this mind when I line a bra I ensure the outer fabric stretches the most, across the fabric, and the inner piece stretches at a 45 degree angle of the outer piece, this ensures that the fabric stretches at different amounts at certain parts of the bra (this only really works with a two way or four way stretch fabric), which will give support of the breast. Also the front underband is curved under the breast so when worn it straightens out for added support.
The first thing I would do is sew together any piece that is doubled up and is not turned to hide the seams. In this case it was the front cups.
Next the neck elastic needs to be attached, this is zig-zagged on. Depending on your skill or the width of the fabric the elastic can be applied on the right side with the elastic edge going inwards then turned and sewn into place, or simply fold the edge of the fabric and place the elastic underneath and zig zag attach. The elastic needs to be sewn with tension so it needs to be pulled slightly, I find the best way to do this is to physically mark your machine and pull the elastic to the mark to get consistency.
The neckline should slightly bow due to the tension you applied. This will then lie flat against the body once worn.
To complete the cups, the front and side sups need to be sewn together. As we are hiding the overbust seam, the front cup piece will be sandwiched in-between the both side cups.
Sewing on top of the seam through the liner of the side cup, will offer strength and neatness.
Next the underband is sewn on, again the cups are sandwiched in-between the outer piece of fabric and liner, so the seams are hidden. At the centre front of the bra I have crossed the cups, on the smaller cup sizes I would just butt the cups together as smaller breasts are naturally set further apart.
The wings are sewn to the edge of the side cups. Again the cups are sandwiched in so to hide the seams. On this style the side cups may look bigger than the wing, this is because the seam is designed to match up with the side seams of your clothes giving you a clean silhouette and profile. The wings angle down for fit, so when they are on the body they will straighten out and give support, creating a shelf type support for the breast. If you're starting out designing bras I would recommend that all your wings/underband slope down. I have designed bras where the band was straight , but these tended to be specialised balconnette bras, and by straightening out the underband you have to adapt the underband and then the angle of the boning.
Next attach the brushed back elastic to the underband and underarm. I have attached the elastic on top of the bra with zigzag then turned it underneath and secured it with a further zigzag stitch.
Next I attach the bra strapping to the back of the bra. This is zigzagged on top of the curve at the back (Leotard strap attachment), I would recommend the curve on the wing at the back when doing larger cup sizes, as the weight of the breast is distributed through the whole curve, rather than inserting the straps into the wing (camisole strap attachment) where the weight of the breast would be just on the two anchor points going into the strap.
The elastic is then threaded through the ring and secured with two rows of stitching going back and forth. In production this would be bar-tacked.
The hook and eyes are sewn on the wings at the back, if I am sewing them on just using my sewing machine I start in the middle so not to have to ease or pull the wing in to make it fit, and I sew down, keep the needle in, turn it around, go to the top, turn it again and finish where I started, this also ensures strength with it having two lines of stitching on top of one another.
The straps are threaded through the middle bit of the slider and sewn to secure them in place, then they are threaded through the rings and back on themselves through the slider again. To attach them to apex, I have placed the straps under the meeting point and secured by sewing in two places, to hide the seam you could place bows over the join. In production the two right sides are usually placed together, turned, then bar-tacked into place, but this can be quite bulky if you are doing it on your normal sewing machine.
To finish the bra off, I added a black 3mm bow at the centre front. I attached it using the zigzag stitch, if you're finding it hard to keep the stitch in the same place, when I was first starting out, I used a button foot attachment which clamped my bows in place.