This has been fun and enlightening to read all the responses.

I went a long time before getting a "slider" and I wish I hadn't
waited so long. BTW..you trim it so feed dogs can be used. If you quilt much you will find a way to make a working extension
table for the support of the quilt top..and the slider helps! I use all kinds of gloves, grippers and finger tips...somedays
one works better than the other! the fusible paper liner works in a pinch..but often has residue that gunks up my iron...so
I used regular applique mat 'till it got krinkle-y and last year got a light duty baking sheet from the cooking store for a little less $.
You can clean them better than the paper.And I can see thru it ! There's always something new to try.
I'm thinking those bags are gonna be heavy !!!