I thought "density" pillows meant they would be dense, but I don't know what the manufacturer/marketers could have possibly meant! I ordered the king-size extra-fill side sleeper pillows, and they are the most airy, lightweight pillows of any size I have ever felt. No support whatsoever. My daughter called them "floofballs". Not a real word, I know, but accurate still. I know pillows are highly personal, but these are as far from the product description as possible. Even the size is off, as they don't fill the case. Not even useful as a sham-stuffer. Ah well.