Doreanse is a Turkish brand of underwear that's quite easily available in the UK, whether through Amazon or DeadGoodUndies. The company has been around since 2004 and it appears that it is a textile maker too (of which Turkey is a major exporter). They have been making a very large selection of thongs and g-strings, along with thong bodysuits, which are rarer as far as I'm aware. They also make underwear and lingerie for women in addition to men.
I bought two, both from DeadGoodUndies, which I think seems to be the main supplier in the UK.
1390 Aire String
https://www.deadgoodundies.com/doreanse-1390-aire-string
Unlike what its name suggests, this string has a thong back although, from the front, it is practically indistinguishable from a g-string. This thong is made of polyamide and as such is very soft and elastic. However, I had a few qualms about it since I thought that the string waistband ended up being smaller than expected, making prolonged wear not as comfortable as I'd hope. The back has a great width for a thong and I found it comfortable. The pouch is snug but also not very roomy; it has a bit more of a flat front which I didn't mind, and that also means there isn't much of a bulge. I think the thong itself looks very nice and sexy, and the quality also appears to be pretty great in my opinion.
Fit: 3/5
Look: 4/5
Comfort: 4/5
Quality: 4.5/5
1330 Micro Modal ECO Thong
https://www.deadgoodundies.com/doreanse-1330-micro-modal-eco-thong
Hilariously, this one is labelled a thong when it is truly a g-string. This one is made of a soft micro modal fabric which I really liked. However, I had the same issues with the 1390 string in that the waistband felt a bit tighter than I'd hoped it would be. Perhaps I'm just not as big a fan of g-strings as I am for normal bikini thongs. This one is a bit more lowrise than the 1390, and as such the pouch is very snug, and I found it to be on the small side. The bulge is likewise not very apparent, but I didn't mind that. The back was very nice though, as I didn't feel like I was wearing anything. Build quality is similarly nice.
Fit: 3/5
Look: 4/5
Comfort: 4/5
Quality: 4.5/5
