Last evening, I was trying to just do simple diagonal basting across a few blocks of fabric for Baltimore Album type blocks. The foundation fabric is tone on tone white and difficult to see. I had ironed the folded lines but it was still difficult to run a simple basting line until… I pushed off the cutting mat, turned the fabric and realized if I laid the fabric across, I could stitch across a straight line with the mat helping me underneath. The mat edge was just enough to feel the straight edge and load the needle up straight along.
Maybe everyone already knew this and does this. I imagine one could also machine baste lines but the problem would still be that they are straight on. Straight lines are a good thing.
