For regular sewing it is recommended that you match the size of the needle with the size of the thread. I do use a 12 for piecing with 50 wt thread on my vintage machines. I do most of my quilt on my Bernina and I use a 90/14 either topstitch or quilting needle and haven't had any problems. You can buy 80/12 needles most anywhere you buy 90/14's, I guess. Most of the places that I buy needles have a variety of sizes.