Baby's Sleep Sack

Here's my latest project. I am working on a baby sleep sack. I've been told babies shouldn't have blankets in the crib, in order to prevent SIDS. A sleep sack (or is it sacque?) takes place of a blanket now. The baby can't get tangled or kick off the blanket. Comfy baby = sleeping baby = happy new mom.

I know there's a pattern on Knitty.com, but I had cotton sock yarn that I needed to use. Yes, it's brighter than my usual knitting, but the cotton feels good as it runs through my fingers. I'm using #4 needles, and getting a loose knit, about 5 or 6 sts/inch.

I made it a lap-front diagonal wrap, it might make it a bit easier to slide the baby in the sack. The chest is 18", so it isn't exactly a newborn size.

From what I read, baby sacks don't have sleeves, they are open for air circulation. The sack isn't intended to replace pajamas, only the blanket.
I don't know how long this will be, I have 2 50 gram balls of sock yarn. I plan to sew any larger sleep sacks, this skirt will be a lot of knitting. Mindless, though, and relaxing.
Details to follow in another post, I have potato salad to make.