Ready to sew some underwear from a t-shirt? Good! Need a pattern? Check out my previous underwear-sewing-post with a free pattern to download!
In this “how to” I’ll be covering the basic construction of underwear with this turquoise and brown specimen below as a sample. Next underwear-post will cover some other alternatives for adding elastic, including fold-over (FO) elastic, and the bare-bones regular kind of elastic.
You will need:
- pattern for underwear
- 1 t-shirt
- ballpoint or jersey machine sewing needle
- regular elastic, or specialized underwear elastic such as fold-on elastic (I’ve had very good experience with this company).
The amount will depend on the size of the underwear, but roughly 2 yards pr piece of underwear?
Directions:
1. Cut out all patternpieces, making sure to stay on grain. Often in t-shirt material there is a distinct horizontal or vertical orientation – line up your pattern pieces with that, not the side-seams or hems if they seem very off. Because of how t-shirt material is often made (knit in the round), the material is often off-grain when sewn up to a garment, and that my friends is why t-shirts twist and the side-seams aren’t at your sides anymore!
Digressing aside, you need one front, one back, and two gusset pieces. For this sample I took advantage of the existing bottom hem, and lined up the top of back and front pieces with the hem.
2. Sandwich the front piece between two gusset pieces along the shorter gusset edge, and sew. Make sure that both gusset pieces are facing right sides towards front piece.
Sandwich the front and gusset pieces (gusset, front, gusset)
3. Roll up the front and back piece *into* the gussets, and line up the longer gusset edge and sew.

Contorting the pieces for an enclosed gusset.
4. Un-wind everything, and it should now look like this:

Not looking too bizarre now. And I’ve done the elastic in the casing already at this point, which really can be done at any time before sewing the side-seams.
5. Taking advantage of the existing hem, thread elastic through the casing the hem creates. Zig-zag or backstitch the elastic inside the seam-allowance of one side. Pull the other end of the elastic slightly to ensure a snug fit, and sew down on opposite side of the casing/hem. Cut off the excess elastic, and do this for both front and back pieces. Note! When adding elastic in another way, skip this step entirely.
6. Sew the side seams. Consider finishing the side seam with a flat-felled seam, mock flat-felled seam, or topstitch the seam-allowance down on either side of the seam. These are mostly decorative, and therefore quite optional!

A mock felled seam for the sideseams
7. It’s time for the elastic! I’ve used some picot edge elastic for the leghole. Line up the non-decorative edge along the edge of the leghole with the right side of the underwear up. Zig-zag using a fairly wide stitch, but not wider than the plain part of the elastic. I usually cut the elastic only when I’m all the way around, overlapping the two ends and backstitching. You can fold one layer under to make the join neater, but it get’s a little bulky and unmanageable. Stretch the elastic slightly as you sew.

The first step of attaching the picot elastic, the right side of the underwear seen in the foreground.
8. Turn the elastic back and under, so the elastic stays flat and the fabric folds under itself. On the right side zig-zag again, along the edge of the underwear fabric . Backstitch.
10. Look at that, you’re done! Well done!
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Did you miss a post in this underwear-making adventure?
If you make a pair (or five?) from this pattern, please share! Comment, link back, and show off!












Awesome tutorial! I can’t wait to give it a shot! Thanks for the resources, too!
My pleasure!
If you don’t use t-shirt material will folding the fabric over and making a seam mess up the pattern? Also… do you use a precut amount of elastic or just cut it after sewing it on? Thanks!
Folding the fabric over and making a seam will make the underwear lower rise. If you want to keep the original shape you can allow for a little extra fabric upwards, roughly an inch perhaps, depending on how much you fold over of course!
As for the elastic, when I use elastic that is being sewn to the fabric, I just keep the roll of elastic in my lap as I sew, and cut after sewing it on. With elastic that is inserted in a folded over casing, I usually just hold the elastic around my waist where the underwear will sit, pull it until it’s snug but comfortable, and cut it to that length (adding a little for overlapping and stitching the elastic together).
Everyone has their favorite ways of doing things, but this is how I do it at least. Hope that helps!
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http://mumtopia.blogspot.co.uk/2012/10/typewriter-knickers.html Here’s my effort – typewriter knickers! Thanks for a fabulous pattern and tutorial. Hope you like them as much as I do!
Oh, that’s perfect! I love it! You are a funny lady. Thank you so much for sharing, you had me laughing!
Thank you for the pattern and the tutorial! I made my first pair this evening. It will be exposed tomorrow blog post on my blog. Awesome pattern, thank you!
Hi Graca! Thank you for your nice comment, and also the mention in your blogpost! I appreciate it! I’m so happy it worked out for you – your finished pair looks great, and it’s such a quick and satisfying stashbusting project. And I agree – the part where the bigger pieces are stuffed inside the gusset looks crazy and confusing, and I always find it a small miracle that it works, haha!
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