Question: What is fill power?
Answer: Fill power is the amount of space in one ounce of down; the higher the number, the higher the quality of down. Good quality comforters start at 575 fill power, and better quality comforters are 650 fill power and higher; the higher the fill power, the warmer the down comforter. The amount of down is also important; the more down, the warmer the down comforter.