The scrim is found on the top and bottom of many types of cotton batting. It is a shear piece of polyester or glue that holds the cotton in the middle of the batting in place. It acts as a sort of stabilizer. As a result, quilters can get by with less quilting; sometimes up to 10″ apart. Without a scrim, quilters using cotton batting have to quilt about 1/2″ to an 1″ apart in order to prevent the cotton from shifting when washed. (Think about antique quilts that feel bumpy; that’s the cotton breaking apart during washing.)
Many batting companies advertise their batting as 100% cotton. This isn’t completely true if the company also advertises quilting up to 2 or more inches apart. The photo shows a bag of cotton batting. On the left side, I boxed “…with a synthetic scrim for strength” which is right across from the circled “100% Natural Cotton.” This batting can be quilted up to 8″ apart.
Check out the video below for more info.