When I first was quilting I bought poly batt that was too thick. My go-to now is 1/4" poly, as I love the way it drapes, and I am not a fan of too-dense quilting. I do not like spray baste, but put a sheet of plywood on my dining room table and tape my backing down with painters tape, then I pin baste [and yes, I also hand baste with a long stitch and remove the pins before sewing].
Your "floor quilt" will probably need a thicker batting than 1/4", but don't get a 1" one or you will have massive trouble quilting it. In my opinion.
How about using one of those 1/4" feet that have a sort of arm where you can set the distance apart in quilting straight lines?
Last edited by Lee in Richmond; 06-15-2020 at 05:50 AM.
Reason: clarification