Face mask is made from 2 layers of tightly woven cotton, with the filter pocket adding a third layer.
I acquired this pretty vintage fabric about 20 years ago and never used it. The cotton is high quality. It is actually a pristine unopened bed set by Laura Ashley from maybe the 1960's.
Elastics are left loosely tied. Please untie and retie into a knot your personal preference. Then cut off excess elastic and rotate and such knot into the fabric casing.
Every mask will look different/original.
Made to order.