Quilt

A quilt is a sleeping bag with the underside removed

A camping quilt is insulation shaped to cover a sleeper from above, open along the back, usually with a footbox at one end and straps that pass under the mat. It looks like an incomplete sleeping bag and that is precisely the design. The insulation that would sit beneath the body is deliberately left out, because it does no work there, and what remains is lighter and less restrictive to sleep under. It is a system that only makes sense alongside what goes underneath it, so the sleeping mat becomes the more important half of the setup.

Why remove the insulation underneath?

Down and synthetic fills keep you warm by holding air in the space between their fibres. Lie on them and that space disappears, since body weight flattens the fill against the ground and the trapped air goes with it. The underside of a sleeping bag is therefore carrying weight and bulk while contributing very little warmth. Dropping it lets the mat handle the ground, which is what a mat is built for.

What has to go underneath?

An insulating mat, not simply a comfortable one. Warmth from the ground comes entirely from what is beneath you, so a thin foam pad on cold ground will undo a warm top layer. An inflatable mat with insulation inside, or foam under an air mat on the coldest nights, is the usual answer. The same logic applies off the ground, where an underquilt hung beneath a hammock replaces the mat; anyone sleeping in a hammock tent is solving that identical problem from a different angle.

How do you stop draughts at the edges?

• Mat straps: the strap system passing under the mat is what stops it lifting when you roll over.
• Closed footbox: a sewn or fastened footbox keeps the feet enclosed, the coldest point in an open design.
• Generous width: enough fabric to tuck under the hips on each side is what seals the edges against a draught.
• Neck closure: a drawcord or a popper at the top holds it against the shoulders, where warm air escapes fastest.

Sharing a double hammock changes the sums again, since two sleepers under one cover need width before they need warmth.

Who should choose one over a sleeping bag?

Side sleepers and anyone who moves during the night, because it turns with the body rather than twisting around it. It also suits people who feel confined by a hood and a zip, and anyone counting grams for a long walk. The open design is less forgiving in wind and on nights near freezing, where the sealed shape and the hood of a sleeping bag do the job with less fuss. For a small amount of extra warmth in either system, a sleeping bag liner adds a layer without adding bulk.

How should it be stored and cleaned?

Loose, always. Insulation left compressed in its stuff sack loses loft permanently, and loft is the whole product; a large cotton sack or an open shelf keeps it alive. Air it after every trip, since body moisture builds up in the fill. Wash it rarely, following the care label, and dry it fully, breaking clumps by hand as it dries.