I believe I have some of this in a drawer. It is for drapes, mostly for a valance. It lets you use a cheaper, narrow rod. You thread this through your large pocket then put the narrow rod behind it. Gives your valance more body. I believe I got mine years ago from Country Curtains.

If it is cloth but feels kind of like paper too, I think it might be the cloth they use for drapes, to make them stiff where the pleats are. I really don't know what else you would use this for unless you cut it into perfect squares and made string quilts, very small string quilt blocks.

Try to join two pieces of batting with it. It may be that is what it is for

I used it once to line a drapery tie-back, it's expensive stuff.

Hope you and your family are OK are Oklahoma!

I use to make my own cloths and I bought what looks like this for collars - waistbands and cuff s stiffener.

Yes, thats my idea too.

It is for making drapes. It is called pleaters tape.
It is for the tops.

Looks like header tape for drapes to me also.

I was thinking the same thing.

looks like backing for emb machines on golf knit shirts