Poly Yarn is a carded material that is part of a 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 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 being completely buoyant.