Yup. Again. I couldn't believe it either.
I once again didn't notice for a whole long quilting session that the backing fabric had folded over and was caught in the quilting...
Can I get away with "At least I haven't made this mistake with the same backing fabric?" Hahaha :)
On the bright side, I'm getting really good at taking out backing fabric without having to tear out quilting :)
Here's my technique: with the tiniest scissors I have (my 20-year-old basic Swiss army knife scissors), I cut really close to the seam, then tug on the fabric from the other side of the seam to pull it loose. It's finicky, but works quite well.
This quilt is now saved! It's the Batik 9-patch, by the way, and this will give you just a tiny sneak preview of the free motion quilting I'm doing. I'm very very excited about it, you'll see why when it's done! :)
21 hours ago