I decided to sacrifice a couple of nicer swimsuits for the sake science* and have been wearing a Charlie by MZ and Todd Sanfield thong in the hot tub, sauna, and steam room at the gym I belong to for about the past year. I always rinse them in cold water and hang them to dry and try not to wear them two days in a row.
The Charlie by MZ thong, which is navy blue with white stripes, is fading. The blue is lighter than it once was and the white stripes and lining sometimes look a touch yellowed, but it’s still perfectly wearable.
The solid black Todd Sanfield thong has held up a bit better. The color is a little lighter, but it’s only noticeable side by side with an unworn black swimsuit.
They’ve both lost a bit of their shape, but they still fit reasonably well, the stitching has held up, and they’re completely opaque. I expect I’ll get at least another six months out of them, if not longer. They’re worn enough that I wouldn’t choose them for the beach or pool, but they’re fine for relaxing after I exercise.
While these are premium brands, they’re not always expensive. If you sign up for the companies’ newsletters and don’t mind waiting for sales, they can be purchased at significantly reduced prices. I’ve been able to get both for as little as $30, which is quite reasonable considering the quality.