I used mostly Superior threads "So Fine" and Aurifil. I like that they are thinner, but still considered 50 weight. When you get into threads like Connecting threads, which by the way, I love to quilt with, you have to adjust your 1/4" seam a smidge because the thread takes up moe room in the seam. Is it that much when your piecing 12" blocks together? No, but the accuracy of smaller pieces can be changed, and you just have to test your seam first. Also, be sure to use the same brand of thread throughout your project, because the different weights of thread can throw you off.