Has anyone made the 5 Hour pattern using baby yarn rather than the worsted weight it calls for? I'd like to use some Bernat Co-ordinates I have on hand but wasn't sure if it would come out too small. Would you still use 10 1/2 needles?
If you used 10 1/2 needles with baby yarn, you'd end up with lace.
You could double the baby yarn and come close.
I made that sweater with Sugar & Cream, a worsted-weight cotton, and I used size 8's. Unless you're a terribly tight knitter, 10 1/2's will be WAY too big!
Some of the patterns I've seen for it have you change the needle size and yarn weight to get different sizes. You can either use size 5 or 6 or double the baby weight.
I recently made it with double strands of sports weight and size 10 needles - came out great!
I'm making this one right now and I'm using the suggested yarn and size 5 needles. It looks like it'll fit a 6+ month old, but I don't have one to try it on. http://www.knittingonthenet.com/patterns/babysweyokecard.htm