real feather pillows » Page not found The fill number refers to the space, in cubic inches, that one ounce of down will occupy. Small clusters take up less space and have a lower fill power number. No real down will not lose its shape or softness if taken care of properly, but a higher fill power number will last longer than lower numbers. If a product has no number, it is not authentic down. Sat, 14 Apr 2018 10:06:31 +0000 en-US hourly 1