Poly-Yarn is a carded material that is part of wider range of colours of this amazing floating material. Poly-Yarn is a continuous fibre that is not bonded so makes Poly-Yarn ideal for bodies, parachute posts, indicators and even as a dubbing. Poly-Yarn has a specific gravity/density of 0.91 g/cm³ so is lighter than water. This means you can rely on this material for your flies completely being buoyant.