Sulky 40 wt. (Lighter) Rayon Decorative Thread Sulky 40 wt. comes in 337 colors. It is a light weight, but exceptionally strong, silky rayon thread. It is colorfast, both washable and dry cleanable. It is recommended that no bleach or whitening agents be used when laundering. While it is a utilitarian weight that works very well in all decorative applications, it is the preferred thread for ""free-motion"" machine embroidery as well as computerized embroidery. Most computer embroidery designs are digitized for Sulky 40 wt. Rayon Thread.A size 14/90 machine needle is most commonly used with Sulky 40 wt. Rayon. It can also be used in the bobbin when working on projects where having the same color bobbin thread as top thread is important. Normally for embroidery work, Sulky Bobbin Thread is most widely used in the bobbin in both white or black. Note: 40 wt. snap-spools have black printing on the spool. 220 yd Snap-Spool - Click on the word "Color" next to drop down box to view color chart!