Extra Warmth, Support and Comfort

There is considerable overlap in the function of a mattress pad (or mattress topper) and that of a fiberbed. Both are placed on top of a bed for additional comfort, support and warmth. In general, they are extra soft so they comform to the shape of your body, and in doing so, improves contact

surface area between your body and the insulating fabric. Whereas mattress pads can be made of foam or other stiffening material, a fiberbed is strictly a soft layer made up of a fabric cover stuffed with a fill material.

Laid Over the Mattress

A fiberbed bears a striking resemblance to a comforter except that it's usually sized in such a way so as to cover the bed with its edges flush to that of the bed. The reason is that the occupants of the bed lie on top of the fiberbed. Any extra material hanging over the side of the bed would not only be wasted, but also extra material would not hang straight down but rather stick stiffly to the side. The reason is that fiberbeds are stiffened with the addition of feathers. Regular down is only made of plumules, the soft undercoat of a goose. The feathers help stiffen the fiberbed to make it have the properties of a mattress.

Taking Out the Down

A down alternative fiberbed is much the same except the internal fill is made of synthetic materials (usually, but can sometimes be another type of natural fill such as wool or silk). The synthetic materials have both a soft component to mimic down, but also a stiffer component to mimic feathers. The result is a down-like composition without feathers.

Advantages of the Down Alternative Fiberbed

There are three advantages to using a down alternative fiberbed. The first is that a down alternative can offer reprieve to certain people who suffer from allergies caused either directly by goose fill or by dust mites that thrive in the goose fill. The second is that a down alternative fiberbed is often cheaper as synthetics can be mass-produced as much lower rates than harvesting geese. The third is that down alternatives don't contain little feathers that occasionally pierce the fabric and scatter the bed area.

Disadvantages

The disadvantages of a down alternative fiberbed, ironically, come from the same reasons for why it holds advantages. For one, down alternatives usually don't have the same high warmth-to-weight ratio of down, but since this is a fiberbed that sits under the occupant, the weight issue only surfaces when you have to move the fiberbed. Another reason is that synthetics are not as good at insulating, so in extreme cold, they may not be the most efficient choice. Finally, synthetics do not endure constant wear as well as down. Over a much shorter period of time, synthetics may lose their "loft" or shift around to create gaps or pile-up in the down alternative fiberbed. To some extent, the last issue can be addressed with a sewn-box or baffle-box design to isolate the fill in compartments that are less liable to lead to shifting.