I have to make the backing tight, not taunt, TIGHT! when I machine quilt. I have it almost like a drum when I baste it and I never have puckers or wrinkles. My big quilts, I have a LA baste them for me and I get too much fullness because the backing isn't basted tight enough. I have to smooth the backing out as I machine quilt it. I have never gotten it too tight to distort, it's all I can do to get it tight enough.