When I finished quilting it - the drop on our bed wasn't as long as I had hoped - so I sewed on a backing extension - mounted it back onto the gammill, positioned a piece of batting - and used the gammill to first 'piece' the two strips I was adding to the top - then quilt them. That addition is the green and purple on the left above. But now the quilt touched the floor - too long - so I cut off 6" of that extension and the quilt is now perfect!!! lol!!
And of course that 6" piece I cutoff did not go into the trash - it is now the beginning of another quilt!!!