Pillows come in a variety of shapes, sizes and firmness, but they all have one thing in common: they're filled with something soft. The most popular pillow fillings are down, feathers, polyester and memory foam.
Down is the softest and lightest filling. It's made from the undercoating of ducks and geese and it's what gives pillows that luxurious, fluffy feel. The downside to down is that it can be a bit pricey and it doesn't hold up well to washing – so if you have allergies or like to keep your pillowcase clean, you might want to steer clear.
Feathers are another popular choice for pillows. They're less expensive than down and hold up better to repeated washings, but they're not as soft. Feathers also tend to poke through the fabric more than other types of fillings, so if you're looking for a smooth surface, feathers probably aren't the way to go.
Polyester is the most common type of pillow filling. It's inexpensive, hypoallergenic and easy to care for – just throw your polyester pillow in the wash when it gets dirty. The downside to polyester is that it isn't as breathable as natural materials like down or feathers, so it can get hot during summer nights.
Memory foam is a newer type of pillow filling that contours to your head and neck while you sleep. It offers great support for people with neck pain or other sleep issues, but some people find it too firm or hot. Memory foam also has a tendency to off-gas (release chemicals into the air), so if you're looking for an eco-friendly option, this might not be the best choice