AURIFIL COLOR PALETTE Grey 40wt 100% COTTON THREADS 3 LARGE SPOOLS. 2600 -- 2610 -- 5004. The 2021 Color Builder Subscription is a capsule of 12 mini-collections, each containing three large spools of 40wt thread -- a warm, a medium, and a dark. 40wt is tremendous for sewing bags and garments, or for when a more defined topstitching or quilting pattern is desired. It is also our number one recommended weight for quilting and machine embroidery. This year we've drawn our color inspiration from 12 magnificent Endangered Species, currently in dire need of attention, advocacy, and compassion. Through our year long marketing efforts, we’ll work toward affecting positive change via increased awareness and targeted fundraising. To help achieve these goals, we’ve partnered with Earth League International.