I use the large, black binder clips when I sandwich. I use my craft table and have done up to king size quilts this way. I smooth out the backing (wrong side up) and clamp it to the table. Lay out the batting and smooth. Then clamp that into place using the same clamps as for the bottom. Then the top with the same process. I might get an occasional pucker but for the most part everything is smooth when I am done. Once I have the center portion of the quilt pinned I undo the clamps and move everything to the next section and repeat the process until complete. Can be a bit tedious on a king with the size of the table but it works in the small space I have.