Are -20 Grad Light Down Quilts Real Bedding Ratings?

What a minus twenty rating actually means

A "-20 grad light downquilt" is German search typing for a lightweight quilt rated to minus 20 degrees Celsius, and it is almost always camping gear rather than bedding. That number is a maker's estimate for a whole sleep system, not a comfort level, and nothing in Australia requires it to be tested. Household down quilts, ours included, carry no temperature rating at all.

Two very different figures get typed into that search box, and they sit about 13 degrees apart.

• "-20 grad" in German: minus 20 °C, which is minus 4 °F.

• "20 degree" on US listings: 20 °F, which is only about minus 7 °C.

The standard those ratings come from is ISO 23537-1, published in Europe as EN ISO 23537-1 and now in its 2022 edition, covering thermal and dimensional requirements for sleeping bags. Its ratings are measured on a heated thermal manikin referenced to a standard man and a standard woman rather than on real sleepers, and they are reported as a comfort figure, a limit figure and an extreme figure, the last being a survival number with hypothermia risk attached. The scope of EN ISO 23537-1 excludes bags for military and extreme-climate expedition use, with a note placing extreme-climate conditions at minus 20 degrees. An open-backed quilt is not the article that protocol tests, so a minus 20 figure printed on a quilt is the manufacturer's own estimate.

What we make in Para Hills West

Nothing that leaves our Para Hills West workroom is built or tested against a sleeping-bag thermal standard. We do not make sleeping bags or backpacking quilts, and no quilt we sell is offered against one.

What our quilts do carry is traceable material and real paperwork. Fabric comes from Weidmann in Germany, our down is supplied by Cedrob, and our Polish Mother Goose down comes from the White Kołuda goose. We provide the Veterinary Health Certificates for every imported shipment, which show the down is free from avian flu along with other known diseases, and under the Department of Agriculture, Fisheries and Forestry's biosecurity rules, imported feathers and down must be treated by an approved biosecurity method and meet the import conditions the department sets out in its BICON database. Shane Grimwade, who owns the business, has been in the bedding industry since 1993 and bought this one in 2001. Care labelling is the one rule that genuinely bites on bedding here: under the Consumer Goods (Care Labelling) Information Standard 2023, which the ACCC administers, prescribed goods including household textiles and bedding must carry care instructions as symbols, written English instructions, or both. There is no equivalent Australian rule for warmth ratings, which is precisely why a minus 20 claim can be printed with no test behind it.

Warmth is fill power times fill weight

A warmth claim is arithmetic, not marketing, and it has three inputs:

• Fill power: the down's resistance to compression. Our products state 750, 850 and 900 fill power.

• Fill weight: how many grams go into the casing. Higher fill power needs fewer grams to reach the same loft, which is why a lofty quilt can also be a light one.

• Baffle height: how much room the down has to expand. Loft is what traps air, and trapped air is the warmth.

That is why our range is sold by blanket warmth from 1 to 7 rather than by a temperature. The number tells you how many blankets of warmth you are getting in a bedroom, and you can read the full scale in our guide to quilt warmth ratings. The Australian position on the fill figures is a thin one: the third edition of AS 2479-2007 was withdrawn on 21 August 2018, which leaves fill power and composition claims governed by the International Down and Feather Bureau's test regulations rather than by a current Australian standard, and the International Down and Feather Testing Laboratory's labelling standard holds a finished product's fill power to within 5% of the claim. What we will say about the grades is where the difference comes from. Hand select Mother Goose down is collected from the breast only, then sorted by hand with only the largest clusters individually selected, which is why goose down commands a higher price and European duck down stays the most affordable filling we use. Against a premium European goose down quilt that comfortably lasts between 10 and 15 years with basic maintenance, that reads very differently per year.

Baffle box and channel construction

Where the stitching lands decides whether the arithmetic survives in use. Sewn-through stitching pinches the casing closed at every seam, which creates thin cold lines you will not notice in a mild room and will notice at the top of the warmth scale. A baffle box uses an internal wall so the down keeps its full height right to the edge of each box, which is how our down quilts hold loft across the whole surface. Channelled construction runs those walls as long channels instead, so you can shake the down towards your feet or your shoulders as the season changes. For the warmest build in the lightest casing, that is the Ultra Light Baffle Boxed Queen, 7 Blanket Warmth, and every baffle boxed quilt sits in one place if you want to compare builds.

Choosing your warmth in four steps

Work through it in this order and you will not over-buy warmth:

1. Pick the size first, allowing for overhang. A quilt that only just covers the mattress lifts at the edges every time your partner rolls, and that moving air is what wakes you up cold.

2. Pick the warmth number for the room, not the city. An unheated or elevated bedroom wants 6 or 7, which is the Baffle Boxed Queen, 7 Blanket Warmth in the standard German Batiste TE100 casing.

3. Pick the down grade to suit your budget. The grade changes the weight and the feel at a given warmth, not the warmth itself.

4. If the two of you disagree by two steps, take a his and hers quilt with a different warmth each side rather than compromising on one number.

A quilt two steps too warm gets kicked off at two in the morning, and a sweated-out quilt is damper and flatter by the end of the week. A heated bedroom, or a humid northern winter, is usually better served three or four steps down the scale. Our article on down quilt grades and sizing sets the sizes side by side, and if you are stuck between two numbers, contact us with your bed size before you order.

Loft you can check at home

A warmth claim is something you can audit yourself, and when a quilt feels flat the cause is usually body moisture rather than the down. It builds over consecutive cold nights in a closed room. Air the quilt, or tumble it on low heat rather than hot, and the clusters open again. Wash a quilt every three to five years rather than every season, store it loose rather than in a compression bag, and follow our guide to refluffing a down quilt when it needs it.

How to measure loft at home

Lay the quilt flat, let it settle for a few hours, then measure the height at the middle of a box and again directly over a seam. A baffle boxed quilt should lose very little between those two points. If the whole quilt measures well under what it did when new, you are looking at compressed or damp down rather than a warmth problem.

Where a household quilt stops

Anyone shopping for a "-20 grad light downquilt" is planning to sleep outside, and that changes what matters. A camping quilt is one part of a system, and the parts we do not make matter as much as the quilt does.

• No head insulation: a quilt has no hood, so a separate down hood or balaclava is a second purchase.

• Open edges: outdoor quilts use pad straps and a draft collar to seal the gap. Ours are built to drape over a mattress, not to clip to a sleeping pad.

• Ground loss: the insulation underneath you is part of an outdoor sleep system too, and a bed quilt does nothing for it.

• Footbox: cold ratings normally need a sealed footbox. A bed quilt is deliberately open so you can vent your feet.

So if you need sub-zero camping gear, buy it from someone who makes it. If what you actually want is an Australian-made down quilt for a cold bedroom, that is the part we have spent 25 years on!