The ultimate luxury fiber combination. Gorgeous natural color or beautiful overdyed. 50/50 yak/silk blend. Available in 4oz. Bundles. Yak down is a truly extraordinary luxury fiber. With a diameter of 15 microns, it is comparable to cashmere in softness while being 10-15% warmer than merino wool. naturally hypo-allergenic, it remains warm even when wet. Natural breathability helps the body regulate it's heat, meaning you stay cool when temperatures rise and warm when temperatures drop. Pair this fabulous fiber with cultivated silk and you have a match made in paradise! Silk is a natural protein fiber spun by silk worms to form their cocoons. The shimmering appearance of silk is due to the triangular prism-like structure of the silk fiber, which allows silk garments to refract incoming light at different angles, thus producing different colors. This silk is cultivated, which means the worms ate a steady diet of one particular type of foliage from one particular type of tree/bush. Usually Mulberry. Silk's absorbency makes it comfortable to wear in warm weather and while active. It's low conductivity keeps warm air close to the skin during cold weather.