It's available at http://www.threadsoftimefab.com

Great question! I lucked out and found some at JoAnns (bought all they had).

I would be more apt to purchase black batting then to dye it, because- what if you wash your quilt, and it bleeds?
and it would really be a hassle if you are doing a large quilt. THen theres the expense of the dye, and having somewhere-
something to put the batting in, like a utility tub, or a bath tub, then you have to clean out the tub..black batting isnt that hard to find- if you know where to look. Try www.connectingthreads.com, or www.nancysnotions.com or even just www.ask.com, just ask where you can buy black batting..piece of cake!
katz

I saw some dyed with rit dye on quilting arts a few weeks ago it is on youtube i'll go get you the addy
here it is I did some fabric but havn't tried batting
http://www.youtube.com/watch?v=egaCOUtyszk