I am making this bag and I am using white linen in place of the black upholstery fabric. I'm at the stage where I have pressed the four edges of the casings and am to sew the bottom edge to the main bag fabric. However, when I go to sew the bottom edge, it is glaringly crooked. Instead of a nice, crisp, pressed edge, it has waves in it and looks horrible.
Does anyone have any tips to get it nice and straight when pressing so that I can get a clean edge?