Yes, I thought I had said it was the bag but when I went back and looked I realized that I hadn't.
I was hoping to warn anyone else who stored batting in plastic bags because I sure hadn't thought the bag would break down so fast as well as figure out how to clean up the bits.
The bamboo batting is gorgeous and soft but I no longer know the brand because the bag is too deteriorated. I am not worried at all that the batting will be a problem once it is cleaned up.