I don't know about masciline underwear, but it's actually quite simple to find feminine underwear without elastic. Instead the whole panty is made of stretchy fabric, and they're usually advertised as no panty lines. What you said is interesting because I haven't worn elastic underwear for a really long time, and I'm only now remembering that as a child, I always had little bruises on my hips where the elastic hit.

I have this too. In general undergarments irritate the heck out of my skin, unfortunately. I’ve found that the extra soft/stretchy ones are usually better! I buy most of mine from meundies, i love them. Their bralettes have also helped me relieve irritation tons, if you wear any of those sorts of garments too. used to be bad around my rib area and inner thighs but their stuff has made it much better. my husband and i have a subscription now to get matching ones each month. 🥹