Staple Ban-Rol Super Stretch Waistband Elastic is perfect for waistbands that won't roll, crush or curl, but still have a little give. You can use it for waistbands in skirts, slacks, shorts and pants. 46% nylon/ 29% lycra/ 25% polyester. 

• Colour: White

• Made of: 46% Nylon, 28% Lycra, and 26% Polyester

• Use: Elastic Waistband

• Size: 1 1/2 inch WIDE 

San Francisco sewing luminary Sandra Betzina uses Ban-rol XL-90 super-stretch elastic almost exclusively in her elastic waistbands, choosing a width compatible with her fabric type. This mesh-like elastic is available in white only and is sold by the yard. She cuts the elastic based on her waist measurement ( minus four inches) and feeds it through a casing using a safety pin. Next, she uses a 75/11HS ballpoint needle to sew several parallel rows of topstitching through the fabric casing and elastic. What looks like separate rows of elastic fed through several casings is one wide band that does not roll, crush, or curl.

https://www.threadsmagazine.com/2008/11/01/the-great-elastic-waistband