Oh this stuff was special - some of it was off kilter in two directions. Luckily I'm married to a guy that just happens to have plexiglass hanging around, so he made me a 9.5x9.5 jig to cut them. If I'd kept working with the straight rulers I would have stabbed someone.
Well, I washed the flannel first, so it twisted a bit. I tried my best to get it back in shape, but it was yick. So, yes, while it pained me, I did end up off grain at times. But my rationalization is that this is a very simple big-block quilt, so I'll quilt the heck out of it to keep it from twisting and being nasty.
If you're quilting the whole thing, you should be fine. It might get a bit weird in spots many years down the road after it's been washed a couple million times, but it will probably be starting to fall apart by then anyway, so no one will care. I just see "I cut it off grain" and the sewing teacher in me has a minute or two of seizures and apoplexy.
