when i first started quilting i hand basted my quilts on the floor, using technique similar to one gwen marsten & jo cunningham demonstrated in their book on basic quiltmaking. now i have an antique fram i use for large quilts. but for mini's, wall & small quilts i still tape down backing ..but to cutting mat on table instead of floor. when pulling your backing taught -not tight- i place tape at each side, squaring as i go ..then progress along sides. but, tho i had never heard the "pinch test" term ...what i do to ensure backing is nicely taught to prevent puckers etc, i sorta test it in middle to check if any excessive give. if so, not taught enough, start over.