Used a cotton/llama blend that is machine washable. Added a large garter border around the whole thing to add extra inches. Not really crib-sized, just large enough to be used as a cover up for a stroller or car seat.
I bought this yarn from a local woman through craigslist and I have a lot, a lot, a lot more of it. Because it machine washed and dried so well, I'll probably use it for more baby things in the future.