We have four nieces that are having babies this fall! My sisters and I were talking about making receiving blankets. The ones that were made for our babies were square WOF, which was closer to 45" 30 years ago. The ones that I've seen in the store look so small.
Since flannel and quilting cottons seem to be ever narrower, I'm thinking about some other options. Dharma Trading Company has some heavy cotton gauze that is 50" wide after washing that I may order. It looks like the same gauze used in a popular brand of swaddling/receiving blanket. Since it only comes in white, I could bind or serge the edges in a color.