How many yards of wool to allow for shrinkage?

[hmhopkins77]

I'm making a sleepbag for my dd. The pattern calls for 7/8 of a yard of 60" fabric. Here's the catch. I'd like to use wool interlock and preshrink it before I sew.

How many yards of interlock (before shrinking) do you think I need to buy for each sleeper?

Thanks!
Heather

[cinnamonamon]

Well, I just bought some wool interlock; this actually: http://diapershop.com/wl200.htm and after fulling it as much as possible I ended up with 5 ft. out of 3 yards. And it ended up about 1/2 as wide too. It is REALLY thick, though -- a good 1/2 inch, I'd guess. I've worked with wool flannel in the past & although I had to use 2 layers for diaper covers, I don't think it shrunk nearly as much. Perhaps that would be more cost efficient & a more comfortable thickness? Good luck!