One of the best uses for blue painters tape is on the bed of my sewing machine. It will mark your seam allowance. If you add a dash mark across from your needle you will be set to sew curves also. Line your fabric up to the blue tape without covering it up and guide your fabric while the machine sews so that it follows the tape.
Sometimes it hard not to look at the needle while the machine is running. But it’s very important to use the blue tape as your guide. You can reposition it many times before it loses it’s stickiness. Most machines don’t have lines that are easy to see or extended far enough to use. This solves both or either of those problems.