Your freewrites are so fun, so full of surprises.
You are the master of the unexpected, and the fresh twist.

I still have some of this stuff in my sewing bins!
I've never used it--too intimidating for me. I've put in one zipper. By hand. No using the zipper attachment on the machine. Nor the buttonhole attachment. I sew buttonholes by hand.
(No, I don't sew. Not really. Just some kid costumes for Halloween, and some mending.)

Interfacing is an extra layer of fabric that is sewn into your garment. It appears in collars, facings, button plackets, and other spots in the garment that need a bit of support and shaping.