I made my own loincloth by practice and error; sew a lot, buy fabrics, see models, etc. And as I researched on the internet, I improved the design until it finally ended the way I wanted. If you like to chat, count on me nwn

I never bought any of my loincloth as such. As I prefer the breechcloth type, all I need is are long rectangular pieces of cloth. I have cotton and linen cloths of dark colours (black, green, blue, brown). Maybe I should try the cotton-lycra mix Aaron has mentioned. These I wear with a broad leather belt, which I find quite comfortable.
My subligaculum (roman “gladiator” loinloth) I wrote about in this forum required a bit of sewing. This I don't wear that often, but the breechcloths had many outings this summer …

Eh, I make my own. Six are leather, two are fur, two are in nice trade cloth for wearing with my First Nations regalia, and there's another six in plain flannel.

On warm days around home, I'm often in a plain red flannel loincloth and, if my hair isn't braided, a matching headband.

This has come up when we've chatted elsewhere, and I can always send you some of the stuff that way. Stuff which originally got me wanting to write about the Middle Stone Age, including some loincloths.