Recently I sewed up a sew swim suit for myself using my own pattern, the Swim & Surf Shorts, and the top from the Supersuit by Rad Patterns. You can read more about both pieces here. I like to make sure I have enough support in my swim suit so that I feel comfortable chasing after my kids, so I added a power net layer with underwires. This method will work for nearly any swim suit pattern.
You will need some power net, a set of underwires, and some bra channeling. Wires can be bought from most fabric stores (although the size selection may be limited) or salvaged from an old bra. Channeling is a bit harder to find but is readily available online. I purchase from Bra Maker Supply.
Cut out a front and back bodice from power net. Of course, this piece will look different depending on the pattern you use. On the wrong side of your power net, mark the center front.
Cut a piece of channeling that is 1″ longer than the length of your wire.
Use a disappearing maker to trace the shape of your underwire on your power net. Place the wire approximately 1″ from the lower edge and 1/2″ away from the center front line. If you are on the larger/smaller ends of the size spectrum, you may have to place them further/closer together. You will have a chance to try the placement before committing!
Next, angle the side of the line closest to the center out about 1/4″ and the opposite side approximately 1/2″ (black lines). If you are a large cup size, you may need to angle them a bit more.
Leave 1/2″ tail of channeling at each end above your line and baste the channeling in place along one of the sides.
One side of the underwire will often have a coloured tip. This is the end that is close to the center front.
Insert the wire into the channeling. It is important to note that you are inserting the wire into the actual tube, not into the space between the channeling and the power net. On the suit I am working on, I cut a back bodice out of power net as well. At this point it is important to sew the side seams and try on the suit to make sure that the wire is in the correct place. You want the wires to be flush against your body and directly under your breasts.
If the fit is correct, remove the wire and stitch the other side of the channeling in place and stitch over the basting stitches you did previously so that both edges are secure. Remember to leave 1/2″ tails at each ends. Repeat with the other wire. To close the center front edges of the channeling, stitch a bar tack over the ends (NOT through the actual power net, just through the channeling). Trim the channeling close to your stitching.
Insert the wires and close the other end of the channeling in the same way.
This is what it looks like when it is done!
I don’t like the feel of power net against my skin, and also didn’t want the risk of the beige power net peaking out from the inside on a black swim suit, so I sandwiched the power net layer between the lining and the outside of the swimsuit. The combination of the power net and the wires make for a very supportive swim suit!