For all my piecing, I use Prescencia (a 60/3 thread made in Spain) in the basic neutrals, but for topstitching, etc., I always buy the cotton Gutterman (50/3), because it is good quality and readily available at JoAnn's. I have not had a problem with it so far and will start looking at the spools to make sure it's not made in Mexico. Aurifil is 50/2, so I don't use it. I use the Mettler Silk (50/2) for applique, but not for machine stitching.