Some of the things to look for when looking at down comforters and down comforter sets are:
THREAD
COUNT: This is the number of threads per square inch. A higher thread
count means a tighter weave for a softer and silkier feel to the
fabric. To
prevent leakage of the filling, down comforters should have thread counts of at least 240.
FILL
TYPE: The fill type is the kind of down used in the down comforters.
Down is the soft inner plumage of water fowl such as ducks and geese.
It has
numerous light, fluffy filaments extending in
all directions, without a feather’s quill shaft. This keeps birds
cooler in summer yet warmer in winter, and
provides
breathable comfort. Comforters and Comforter Sets with these fillings
are more comfortable than synthetic filling due to their ability to let
moisture
such as perspiration escape in a process known as wicking. One never
feels clammy with quality down comforters. Simply put, these comforters
are
more comfortable in varying temperatures and climates than other materials.
FILL
POWER: Fill power is a measure of the quality of the down. It is the
number of cubic inches that a single ounce of down occupies. Typical
down comforters are 500-550 fill power. Higher fill power ratings
indicate that a single ounce of down occupies more space and is of
higher quality. Higher fill power means more warmth with less weight,
creating a better way to sleep comfortably and healthier. Higher fill
power down is also fluffier in appearance.
BAFFLE
BOX CONSTRUCTION: Baffle boxes are walls inside dwon comforters that
allow the down to expand to its fullest potential. Baffle walls help to
give comforters the appearance of depth. Baffle box construction is of
a higher quality than sewn-through stitching.
SEWN-THROUGH
STITCHING CONSTRUCTION: Sewn-through stiches go through the top of the
down comforters and emerge out of the bottom. They keep the down in
place and is a more economical form of construction than baffle box
construction.