I heard somewhere on tv that if you soak 100% cotton shirt in saltwater and bleach, it makes the shirt soft and thin. Does anyone have pretty good instructions for this?

I don't have any instructions, sorry... but I wanted to post because I've been kind of curious about that too. I hope someone here knows what to do. ;)

damn that Zac Posen. Actually if you do it with a shirt that is 100% cotton you will end up with clumps of cotton in your solution. So no 100% cotton. I do this with like 2 gallons of warm water (per shirt) a tiny bit of bleach (about 3 teaspoons) and (1/2 cup) sea salt. and i leave it there for about a day or 2 then i wash it.
if your first starting to do this i would do it in stages.

haha yup that Zac Posen, thanks for the instructions :)

if 100% cotton is no good, what do you suggest? 50/50? i prefer 50/50 to begin with, so if they can be even thinner and softer, i'm all for this experiment!!

out of curiosity, why would you want to make cotton thinner? is it for really thick t-shirts?

I think its for making the shirts look and feel 'worn in' as if they've been worn and washed for years. It's usualy more comfy that way, as the shirt's less stiff...