How every bedding evaluation is measured

Each comforter is inspected against the same shell, fill, and performance criteria, using the same laboratory apparatus, so readers can compare products directly.

Shell materials and thread count describe the outer fabric. Air permeability, down-to-feather ratio, fill power, purity, and turbidity describe the fill and how it performs.

Shell materials are recorded by fiber composition and weave. Thread count is measured per square inch. Air permeability is reported as airflow through the shell. Down-to-feather ratio, fill power, purity, and turbidity are reported from the sampled fill.

Units are bought at retail, without identifying ourselves, so the sample matches what a buyer receives.

Shell weave, thread count, and air permeability are recorded before the fill is touched.

Down-to-feather ratio, fill power, and purity are sampled from the fill under controlled conditions.

Independent laboratories confirm fiber and turbidity results before a report is published.