[QUOTE=Peckish;7855652]Probably your last sentence is what I would have done - pinned it horizontally. Here's why it's better than vertically? [\QUOTE]
I just noticed that the backing on your machine is pieced with the selvedges still on. To me, I would not take the time to quilt something with that seam. It is just about guaranteed to shrink weirdly the first time it was washed, and guess who would get the blame? Just my thoughts...