I found this about scrim. “Scrim” describes a light layer or grid of woven fibers added to some cotton battings. It acts as a stabilizer and helps to hold the batting together while quilting. This can be a good safeguard if you're just starting out, or if you prefer a design with wider spacing between quilting lines.
Here's an interesting article about scrim.
https://artfabrik.com/tutorials-2/ho...de-of-batting/
I think scrim is a good thing as it helps hold those fibers together.