Sewing

I have been taking some drapes and cutting them off so they will be shorter. I had to sew a 3 inch seam in them for the rod pocket. I realized that may sewing machine doesn't have a mark to sew at 3 inches. So I marked 3 inches out from the needle and put a long piece of masking tape. It makes it so much easier to sew and I never get off, when it comes to the 3 inches that I need