Step 1: Tools and materials
- fabric with at least a side-to-side stretch
- asymmetrical lingerie elastic for edging
- strap elastic
- hooks & eyes
- a little knit interfacing
- optionally, stretch lace for decoration
- optionally, ribbon for decorative bows
- optionally, plastic hardware for adjusting the straps - but I leave this out b/c I can make the straps the exact right length without need for adjustments!
Step 2: Pattern
There are four pattern pieces:
- upper cup
- lower cup
- front stay
The cup pieces need seam allowance except for the top of the upper cup (you have a couple options there, see the Cups step). The side/back piece only needs seam allowance at the edge that attaches to the cups, as the rest of the edges will be finished with elastic.
I'm not adding the bra pattern here because it will almost certainly not fit you, you'll have to do a bunch of alteration on it anyway and it's really hardly any more work to trace it from an existing bra that you know fits (or know exactly how it could fit better).
Step 3: More on adjusting the pattern
There are any number of possible adjustments to make but the most common are these:
- cup shape, which can be adjusted by changing the curve of the top of the cup lower piece. A small adjustment here goes a long way so change an eighth of an inch at a time, and make sure to smooth out the lines well. If you have to make a lot of change here you'll probably also need to adjust the cup upper as well, making it slightly longer or shorter to accommodate the difference in length of the lower cup edge.
- center stay. May need to be shorter or longer, depending on how widely placed your breasts are. You may also find that changing the angle of the sides gets you a better fit, either straighter or more flat of a triangle.
- cup top edge - I found I wanted my bras to be slightly less than full coverage, so I lowered the outside edge of the cup (but not the inside edge). This also meant I had to make the straps longer to make up for it.
- side/back too short or too long. Make adjustments to this piece in the underarm area.
Step 4: Cut
Step 5: Cups
Finish the top edge of the cup in any way you want. Here I added a stretch lace piece, but you can also use a piece of lingerie elastic, or if you think ahead you can cut two upper pieces and self-face the edge. In that case you probably want to do the edge seam first and then sew both upper pieces together to the lower piece.
If you put on stretch lace like I did, it will probably be easier to sew it on before sewing the cup seam! You want the lace to be a little smaller than the cup (it stretches after all). Place it with the lace edge along the top edge of the upper cup piece, and sew it on with a small zigzag stitch. Finally trim the original fabric piece out from under the lace -- or leave it if you like the overlay look!
Step 6: Center stay
Step 7: Sides
The sewing technique for attaching lingerie elastic is explained in my Panties instructable, in the step about the leg elastic.
Next, sew the sides to the cups, matching top edges, similar to how you sewed the center front stay, a bit less than a quarter inch seam allowance.
Step 8: Underwires
Now fold and wrap the underwire channel around to the inside of the bra cup, releasing the stay and the side piece. It should rest a little more than a quarter of an inch inside the cup, and cover all the raw edges. Stitch this in place close to the folded edge of the channel.
Stitch a bar tack across the end of the channel by the center front stay, so the underwires don't come out. Now insert the underwires from the outside edge by just sliding them in the channel you made. The underwires are not symmetrical; there's a shorter end and a longer end although sometimes the difference is small. The longer end goes at the outside edge.
Step 9: Side elastic and straps
Once the side elastic is on, figure out the strap elastic length. Stitch one end of the strap elastic to each of the remaining back edges without elastic. Now you can pin the bra on yourself and determine how long the straps need to be.
Stitch the strap to the cup, right sides together, where you marked. Cut the elastic if you haven't yet, and fold up the strap so you can stitch the cut end down in a zigzag like in the last picture, to keep it tidy.
I didn't think to do this, but if you have an old bra that's worn out but the straps or strap hardware is still good, you could reuse those parts.
Step 10: Hooks & eyes
First cover the raw ends with something soft - a scrap of T-shirt fabric works great. I simply cut a square, stitch one end to the right side of the bra ends, fold the sides under, and topstitch them down.
Then just sew the hook & eye down, by hand or by machine, making sure there's enough tail on the eye end that the hook won't scratch your back when you wear it.