Something I learned from this board is the use of a few neutral colors for piecing. That was a big mental change for me after many years of "garment" sewing that always meant standing in front of the thread displays matching thread to fabric lol. Because of this change I purchase mainly Aurifil 50 wt for piecing because my Babylocks love it, and along with my walking foot have helped me more consistently maintain a scant 1/4 inch in piecing . Those that have said its a very individual decision are giving you good advice because it really does depend on your machine and the look you want to achieve. If selling is what you're hoping to do, I hope you find a successful way to do that. Happy creating!