Definitely, this is hand-dyed.
Your white haloes are simply the resist lines from the string where it was tied, yes, in a very organic and free form matter.
Results will vary upon many, many variables : what kind of string was used, how tightly the string is wrapped, was it soaked in soda ash water before tieing or after it was tied, which set of hands did the ties etc. , but basically you'd go about it like this:
1) start with a white shirt, the thinner the better for sharp lines.
2) wet it, wring it out well
3) scrunch it
4) tie up little bits of it, very very tightly (these will be your red splotches and some of the white)
5) lace up the whole thing, not so tightly this time so you have a bundle of shirt easier to handle
6) dunk the whole thing in your base color (here, orange)
7) let sit to batch ... or not (either will work; the effect will be similar though probably different)
8 ) if you let it set, rinse it out, if you didn't you can got straight to the next step
9) dye again : over-dye the little bits sticking out that you tied up only with the dark red
10) let the whole thing sit to batch and cure; don't rush it -- a full 24 hours at room temp is better for a clean washout
11) after 24 hours, rinse out the whole thing-- do not untie it yet
12) when water runs clear, untie and ... see what you got!
13) finally, wash in hot water with synthapol or mild soap
As mentioned, your mileage and results might vary, but this gives you some idea as to what kind of work went into this. I hope it help! (fantastic creative work in your etsy store, by the way!)
~Dar
Shibori Borealishttp://shiboriborealis.com/