The first number is the weight of the thread the second is the ply. For piecing and bobbin I like the 2 ply. Tristan sells cotton mako which is the same as Aurifil which they are clearancing out. Aurifil is just a brand name.
Rayon is more for machine embroidery. Sulky makes different types of thread, not just rayon.
Last edited by Onebyone; 11-05-2014 at 07:01 AM.