The undies that I made for this experiment are all from old T-Shirt backs, the fronts of which will one day feature on a T-Shirt quilt. Some of them are really old, I'm talking 20+ years, while others are only 5 or so years old. I did have an issue with my needle making holes while I was sewing them, especially at the side seams, so I liberally used fray stop so they wouldn't get any worse. I changed to a new needle, and still had the problem, so changed again to a different type of ball point needle, again new, and it was still happening! I finally put it down to the age of the fabrics, and the fact that they were already worn out, and the fibres were no doubt starting to break down.
Next problem - I hadn't bought any elastic for my undies, but I did have an assortment of bits and pieces to try.
Underwear elastic - pretty flimsy, I didn't stretch it out enough so the undies are too loose
Underwear elastic - quite a firm elastic, but based on the result of pair number one, I stretched this one too much, so they ended up too tight. Worth fixing? Maybe.
Fold over elastic - really good. These might actually be wearable
Bra elastic - worked well, but stretched it out a bit much, and the fabric itself didn't have as much stretch in it.
Bra strap elastic - worked surprisingly well. It wasn't an obvious choice for undies, but I have an overabundance of this narrow elastic (7mm wide), and while I was trying out everything else I had, I thought I'd give it a go.
I also tweaked my pattern a couple of times as I went. For the first three pairs, as the comfort level changed so much from pair to pair, I assumed it was all due to the elastic, but by the time I finished the fourth pair I realised that I needed to add to the width, so put in an extra few centimetres at the side seam. The fifth pair I was thinking I actually got right, until I wore them for a whole day! I had sewn the elastic directly to the edge of the fabric with a 3 step zig zag, but it has a tendency to roll under on the lower leg. I will make a note of how much and trim this off the pattern. Also, further to my previous theory that the fabric may be too far gone, I can confirm that it most definitely is not going to work to use more of these really old T-Shirts. I put my thumb straight through the back of the blue pair when I pulled them up! I didn't quite get a full day's wear out of them before they'd already had it. Oh well. At least they were comfy, and I can probably re-use the elastic on another pair.
When I make more (out of some not-quite-so-old T-shirts), I can try them on before adding the elastic, and if the fabric has more stretch I can remove some of this extra width before adding the elastic. I'm looking at my son as a future source for T-shirts. He has a tendency to chew holes around the necks of his T-shirts (which I'm really hoping he will stop doing soon), so the rest of the shirt is fine! Not sure if I'll get the back piece of the undies out of them though.
So that's five T-shirt backs stashbusted. Not sure how I'll account for that with the stashbusting, but you can be sure that I will!
I'm still on the lookout for the best elastic for the job, but I have plenty of the black fold over elastic, and white bra elastic and bra strap elastic on hand if I feel the need to make more undies sooner rather than later.
Do you have an unusual success story with elastic choice?