I have tried on many merino wool thongs over the years, and prefer them becuase I hate panty lines! Other merino wool brands I tried never fit properly becuase they are always too narrow between the legs and dont provide enough not enough coverage there, or the fabric is itchy, or they stretch out after being washed, not these! Woolly brand is super soft and not tight at all, with the right amount of stretch. They cover where it counts and dont twist when I hike. I live in humid Florida and wanted a natural fabric that is breathable, dries fast and doesnt smell, and this fabric is perfect. I did 20 miles on the Florida trail this summer and didnt notice they were there. I am heading up to Whistler, BC in the fall, and will to try them in colder weather, I am sure they will be great. My only issue is that they keep running out of my size so I always have to wait for more.