I love power mesh and I’m not a bra maker (not yet anyways. Someone get me a couple extra hours for each day then we will talk). This stiff but supple fabric is like elastic, but with a modern point of view. That is exactly what I use it in place of- elastic. Why, because it is super thin, has great recovery and gives just enough grip to feel secure, but does not make you feel like you have a bungee cord around you.
I use it for waistbands where I want the final result to be flat, no gathers. Even when I do this with elastic, it still gets thick, but not power mesh. With a contour waistband (like I made for this version on the Pinot Pants) I just cut a single layer of the power mesh to be included in the normal waistband seamings- basically you treat it as you would an interfacing (minus the whole fusing thing obvs). It gives just enough grip and where you could just rely on the stretch of your fabric for the elasticity, and it will give the fabric some support so it doesn’t stretch out of shape.
Check out my photos below where I totally overdid the construction in many ways, but I think it will give you a bit of inspiration to utilize it as you find best for your project.
Note: When you put the pants on for the first time you will hear a bunch of cracking noises. This will be the basting stitches breaking unless you remove them.
Oh, one more thing:
How can you tell it's power mesh? Could it be used for a slingshot? Yes, then you have got the right stuff!