Density, Pore Size, and Containment

Pillow and Quilt Shell Fabric refers to the external cover of the item. For down and feather products, the shell requires a high-density, tightly woven structure, typically 230 Thread Count (T230) or higher, with a specialized finish (Down-Proof Finish) to seal the minimal pores and prevent sharp quills from penetrating the surface. The fabric is often a lightweight cotton or cotton/poly blend that is Calendered (pressed under high heat) to further flatten the yarns and reduce permeability. The primary function is to combine breathability with absolute containment of fine fill materials.

Shell fabrics must be durable enough to withstand continuous manipulation and sleeping pressure.