How-To Swimsuit Sewing Part I

I'm just going to admit that I am by no means an expert on making swimsuits, but I do enjoy the challenge for myself. So, it's a project I can have fun with and they don't take that long (especially after you've made a couple)! They can also be a lot cheaper!! You can use general polyester sewing thread. You'll want to make sure your machine is in good shape so you don't get missed stitches. And, definitely use a stretch needle! A serger is also so very helpful and professional looking!
This tutorial is to walk through making a 2-piece swimsuit. Part I will be on making lined swimsuit bottoms and Part II will be on a swim top. I used Mccall Pattern 5400 for the bottoms (the above left picture is a pattern picture; there is a thinner and wider waistband; I sewed the one with the thinner waistband). Whenever I use a pattern, I like to make a mock up first (because they don't take that long) with a cheaper solid (black is a great, versatile color) fabric that I purchased with a coupon (if it fit's, you get an extra pair of bottoms, or you now know, what needs adjusting)! After I made my mock up, I found that I could cut a 1/4" from the front and back at the crotch to tighten it up a bit around my bum. So, now, I have a swimsuit bottom pattern that will fit every time I make it (that is if I'm using the same fabric type - knits stretch differently and will fit a little differently, check out this site for more information). Without further ado, let's dive in...
Remove pattern and open: Here is the back and the front of the bottoms opened up (my lining looks identical to this).
Below is a close up of the last picture (it's flipped, FYI).
You'll have to stretch the back piece (at the crotch) to fit the curve of the front piece. Notice that they do not match up exactly (where my index finger is). The M5400 pattern says that you'll use 5/8" seam allowance, so it will match up right at that 5/8" line. After you've pinned the center and pin the sides of the crotch seam, stretch between your center pin and your outer pin and pin in between to allow for even distribution of the front to the back. See picture in step 3 to see how the entire crotch is pinned.
This is a close up of the side seam, notice the un-alignment of the side seam (this is what I was trying to explain also with the crotch seam). This allows for the proper amount of seam allowance.
Just a little FYI, shown below, your bottoms may "crinkle" a bit at the crotch seam. Don't worry, most of the time it will stretch and lay just right when worn. If you'd like to try on to test out fit, you may, but remember that the elastic seam/hem allowance will take care of some gapping and pull the bottoms in to fit curves (but, that's why I also, recommend making a mock up first to alter your pattern for better fit).
Just a close up...
Here they are completely pinned at the leg holes and waist (sorry, the fabric is so busy, it's hard to see the pins)!
Here is a close up pinned at the leg holes.
A close up...
Another close up...
10. Zig-zag sew your elastic on, stretching it to fit. (The zig zag on my Baby Lock sewing machine was set at 4.5 width and 3.5 length).
Elastic completely zig-zagged on, shown below.
So, you'll turn your swim bottoms right side out and fold your waist down one elastic width (shown in your pattern, as well). In the picture below, I have folded my elastic under and pushed the waist underneath (I did have to alleviate some presser foot pressure on the Baby Lock Diana as it is kind of thick). I also started just after a side seam and I lined up the edge so that I'd be stitching close to the bottom edge of the elastic (so that it won't roll out when worn). Just an FYI, do some test stitching before stitching on your actual fabric. The seams are pretty thick, so, hold tight at front and back when you approach a seam and don't stop or slow down while going over it.
Showing the cover stitch on top here. After you stitch all the way around and overlap your end stitching over your beginning stitches (about an inch), roll your handwheel towards you once and backwards once to unlock the stitches. Then, lift the foot and smoothly pull your project out.
Here is the back side. I have a serged edge, a zig-zag from sewing my elastic on, and a cover stitch from my Diana Serger.
The cover stitch looks so awesome and professional!
Finished product!
Here I zig-zagged instead of cover stitching. My Baby Lock Sewing Machine was set at 4.5 stitch width and 3.5 stitch length (test what you like before sewing on your actual garment).
Finished product with a zig-zag finish rather than a cover stitch.
Have fun! Let me know if something doesn't make sense or kindly add a comment if you have any helpful tips for sewing swimwear fabric!