Lightwave Firelight sleeping bags use Polish goose down with a minimum fill-power of 900 cubic inches as measured by the Lorch test EU norm (more on this is below). This down is collected as a by-product of the goose meat industry.
Down works as an insulator by trapping air. The more air that is trapped, the greater the loft of the down. It is by this loft that the performance, or quality, of down can be measured. The volume a fixed quantity of down will occupy is commonly referred to as its Fill Power (FP).
Although the basic method of measuring fill power is consistent, there is no actual universal standard. Most down products in the Outdoor industry are currently rated according to the Lorch Fill Power standard recommended by the Swiss-based International Down and Feather Laboratory (IDFL), although many (particularly US brands) use an almost identical American standard. Both systems measure fill power in cubic inches. The higher the number, the greater the volume and thus the greater the ability to trap air.
500–600 EU (530–640 US) Acceptable quality for mid-market products
600–700 EU (640–750 US) Minimum quality for performance products
700–800 EU (750–860 US) Excellent quality, best performance/price ratio
800+ EU (860+ US) Outstanding quality, limited availability, high price
It is worth noting that many manufacturers do not state the norm used to establish their fill power specifications. In these cases, assume it is the US norm as it is always a bigger number, so looks more impressive. Beware also of down described as “European” – the implication being that the fill power figures are also the European norm, but if these are not explicitly stated, you should assume they are the US norm. (The delights of marketing games).
Down with a fill power of 800+ (EU) is extremely good, and in fact it is difficult to consistently market products filled with down of higher than 850 (EU) fill power. Whilst the Firelight range has 900 (EU) fill power down, we make them in small numbers only.
Down comes from domestic birds (wild birds have down too, of course, but this is far more difficult to collect!). Domestic birds – chicken, turkeys, ducks, geese – are available all around the world, and the collection of down is practiced everywhere. To obtain a fill power of 500 or above, it is widely acknowledged that the best source of down is waterfowl – ducks or geese.
The common view is that goose down is best. In fact, at the lower end of the fill-power spectrum, e.g. at 600 FP, there is no difference between duck down and goose down. A duck down with a fill power above 750 is rare, however, and it is here that goose down truly comes into its own. For high-performance sleeping bags with fill powers greater than 750, the source of down will inevitably be geese. (An exception is the eider duck, but these are a wild species and the annual quantity of down recovered is tiny – a couple of tonnes - and subsequently extremely expensive. Eider down isn’t used at all in the outdoor industry).
Fill power can be highly variable even in the case of goose down, however. Environment and the age of the bird are two major determining factors in this respect. It is widely believed that the colder the climate, the better the quality of the down. This may be true, but it remains to be definitively proven and it certainly does not mean that high-quality down is not available from warmer climates – because it is.
The age of the bird is very important. Since down collection is usually a by-product of the meat industry, most down comes from (increasingly) young birds. However, the very best down – i.e. with a fill power of 750 or more – invariably comes from mature birds, which have larger down clusters and more of them. As Poland has established a goose breeding industry (for meat), it has large numbers of mature, adult female geese. These birds moult naturally every six weeks (on average) and the down can be collected by hand-brushing. This can only be done in the six months outside of the breeding season, the mother geese being impossible to handle when they have young to protect. Although this is referred to as “harvesting” by the Poles and is a substantially less invasive, if not painless, process for the geese, it still challenged as unethical by some of the more extreme animal rights groups. Nonetheless, the mother geese do eventually come to the end of their breeding life and are killed for meat, and this quality of down can be recovered in a less controversial way (albeit in smaller quantities).
What is important about Poland as a source of high quality down is that it is, at the time of writing, the only country in the world to ban both the live-plucking (as opposed to harvesting described above) and forced feeding of geese. All down used by Lightwave comes from a vertical meat-processing company for whom down is a valuable by-product.
Down “quality” is often additionally expressed by the ratio of down to small feather, written as 90/10, 95/5 etc. This is of no relevance. If a fill power of 800 is measured, then whether it is a 95/5 or 93/7 mix is unimportant. Furthermore, there are no standards at all for defining or measuring a ratio of down to feather.