I hand baste and quilt in my lap. For king size quilts, I assemble in six, 20 " strips, quilt the strips, then assemble the strips and finish quilting over the strip line. The final quilt size is 20"x6" 120". Notice that each strip, being 20inches uses 42" fabric cut on the fold to give 21" and 1/2" seams for the backing. (no waste). Quilting large quilts in strips reduces the weight on my shoulders and arms, and is easily managed.