I did cross hatching on a fairly good sized lap quilt--I think it was about 60 x 60. I used masking tape to mark it, and did it on my domestic machine. It was an applique quilt, and I didn't sew over the appliques. I did 2 of them for my DGSs and they turned out great. I don't like to mark my quilts with markers, too afraid the marks won't come off.
Sue