I realize this is an older thread, but I just wanted to make note that this is not really meant for home. It was designed by a photographer Marta Locklear (www.martalocklear.com), who sells the cocoons and the pattern on her etsy site. It is a prop meant for photography. If you’re looking to have something for your baby that you want to use on a regular basis, try Marta’s baby skins. They are far more practical for daily use.
I know this thread has been quiet for a bit, but I have been looking for a free pattern for my new grandson and came across this one. It may be what some of our knitsters are looking for also. It looks to be easier to get on and off, and is perhaps more comfortable for the infant…more room for arms and legs to wiggle a bit;not sooo confining. The fabric also appears to be tighter so no tangled fingers or tootsies 
. Also, may be cute for my 4yr.old granddaugher’s dolls. I hope this helps someone.
http://nittineedles.blogster.com/baby-cuddle-sack-hand-knit-free-pattern
When my son, (now 34) was a baby, he LOVED to be cocooned. I think we called it 'swaddled" back then.
This looks like a good idea to me. I would have used one on him, cuz the wrapping I did with a blanket sometimes came undone, or too loose.
I wouldn’t use wool until sure that baby isn’t allergic to it. Besides, you’d probably be washing it frequently, maybe daily…so I’d make a few, and in something washable.
Good luck!
Would this fit your needs?
Very cute! Thanks…now I want to knit one!!
Hi,
I have a new grandson on the way and just saw the cocoons on the web. Here is a site of one that looks like a decent pattern that I plan to try.
Harriet
I also designed one for a round knitting loom.
http://www.blogster.com/nittineedles/baby-cuddle-sack-on-loom-free-pattern