Throw pillows can be stuffed with any number of materials. Your choice will depend on the use to which you plan to put the pillows.
A good all-round medium is Styrofoam. It is clean, light and comes in various sizes to provide just the density you want.
Foam is a good stand by and is welcome for the cuddly effect and the resilience that it lends to shapes.
Cotton fibers are affordable and provide a good level of support.
Artificial fibers have come a long way and those that are hollow provide a very warm and friendly experience.
Decorative pillows often benefit from being stuffed with unconventional organic materials. Buckwheat hulls are ecologically friendly and provide an all round supporting roll.
For the very latest thing why not try memory foam? This provides a whole new range of experiences when dealing with pillows.
Feathers and Down
At the top end of the scale are feathers and down. There is no doubt that the extra cost also buys a better experience but is a throw pillow really the place for goose down? Consider your budget, your allergies (down doesn't work for everyone) and how much support you need. You can easily find a filling that meets your needs exactly.