When sewing leather and vinyl, use all-purpose or polyester thread and size 14/90 needle. Use a non-stick foot to help fabric layers feed smoothly. Use binder clips or paper clips to hold fabrics together, as pins will leave permanent holes. Set stitch length for 2.5 - 3.0 mm, as shorter stitch length will likely perforate the fabric. Rather than backstitching, use a hand sewing needle to bring the upper thread to the back side, then tie off. | Singer Sewing