I have a really really old down pillow, and when I opened the pillow to change the ticking... what was on the inside was the equal feather dust. Over the decades of use the feathers had broken down into tiny particles ( maybe that's why I found it so comfortable) Then , I the remembered about how many dust mites can be found in pillows so I tossed the contents and bought a new one. It will take some time to break this one in .