*Product cannot to be sold on any 3rd Party site such as Amazon, Etsy, Ebay or any other 3rd Party sites, unless approved by the manufacturer.* The 2021 Color Builder Subscription is a capsule of 12 mini-collections, each containing three large spools of 40 wt thread -- a warm, a medium, and a dark. Wound on a bold green spool, Aurifil's 40 wt/2ply thread is every bit as versatile as our 50 wt but with just a bit more strength. 40 wt 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.