I had to look this one up - you made me curious! Here is what I found:
Cotton with scrim binder is needle punched cotton batting with a thin polypropylene binder. The scrim binder
provides additional strength which enables the product to be quilted up to 8-10 inches apart, or used as the outside layer for craft projects. This batting is primarily for machine quilters.
I hope that helped. i've never heard of this before!!!