Chicalot, is this it? http://beeinmybonnetco.blogspot.com/2015/08/seams-sew-easy-is-here-and-farm-girl.htmlt, Can't wait to see how it works! Please let us know how you like it.
That's the one. It's a thick plastic. You have to cut a ssquare out of it. I don't recommend using scissors for that. I used some tiny cutters tosmooth the eedges so it wouldn't snag the edges of the cloth. It works really well and I like it. However, I think I would like it more if it was a more flimsy self-adhesive plastic. It works well though and can be removed and used over and over easily