You know, when it comes to cotton, what iv always used is my missus's makeup wipe cotton pad things that are circular, it says 100% cotton, it has like two outer layers of like woven cotton, I use them layers on mini micro coils like for my mini pro tank 2 which is hooked up to my Itaste 3.0 vw @ 1.2ohms @ 10w. its great because its small, can fit in pocket well and I take it when ever I go out my house, and I used it for a full year until 2 weeks ago when I got my kayfun.
But the cotton though, like I said I use the outter layers of the pad for the kayfun, because the woven texture of the sandwiched layers of the makeup pad things, it draws liquid up it a lot quicker to the coil, so its good for miniature micro coils to get the liquid there fast without dry hits at high wattage for such a small coil in general and tank etc. the coils for the pro tank 2 mini are wrapped around a cocktail stick, it works perfect. literally took me months to perfect it, 30g kanthal, 8 wraps. perfection.
But on my kayfun, the same idea flooded it using that part of the cotton pads, but the coils I make for my kayfun are about hmm 2x wider, I use the cotton from between the two woven parts of the pads, its like regular cotton like cotton balls I guess, does the job perfect. 1.6ohms, 18w 30g kanthal 10wraps. I couldn't get along with 28g, I did everything I could to make it work, but the coil would dry hit or foul or do something not right after 3 hrs. no idea why I mean theres not a massive difference between the two, I did everything to 28g blow torched it the lot, I cant figure out what is wrong with it but it wasn't working for me.