As with many of the things I do/make, this little project was sparked by a desire to not spend a ton of money (she outgrew these weeks ago and I didn't want to spend $30 on the three of the next size up). And a bit of a dilemma. The dilemma: Since she outgrew her swaddlers, there were exactly 2 blankets we liked to use to wrap her up- one very thin fleece one and one very thin knitted one. They're both stretchy, which allowed me to pull them tight around her, which I think is the secret to getting a swaddler to stay swaddled. She always kicked her way out of the flannel ones within moments, it seemed like. It's possible I'm just not great at swaddling (I think I've used this word in every way possible now).
Anyway, my solution was to buy a yard of stretchy knit fabric, cut it in half, and serge the edges.
Oh, I rounded the edges, too.
I bought 2 yds of fabric, one of each color, so now I have 4 blankets for a total cost of under $10. And I won't have to panic when one of them gets spit up/pooped/peed on, since I'll have more than one acceptable swaddling blanket waiting in the drawer. Ah.