The thicker the down jacket, the warmer it is? Duck down or goose down is better? Understand these to avoid being cheated...

Expert of this article: Zhu Guangsi, science writer, member of Beijing Science Writers Association

The weather recently has been like a roller coaster, and the temperature suddenly dropped.

In many areas, winter comes in a second. How many of us have quietly taken out our thick winter clothes?

When it comes to keeping warm, down jackets are an essential winter garment.

So the question is, did people have down jackets in ancient times? Why did people choose duck or goose feathers for down jackets? Does a thicker down jacket keep you warmer? Let's find out.

Were there “down jackets” in ancient times?

Bird feathers provide better warmth than silk, cotton, linen, animal skins, and wool.

Feathers have many branches and are fluffier than other fibers. They are hollow inside, so they can contain more air, which is the best thermal insulator.

The so-called down is a mixture of "feather" and "down". Feather is the harder part of feathers, which plays a supporting role in down and makes it elastic; while down is the down flower, similar to the head of a dandelion, which makes the down fluffy and warm. The big and hard feathers can be used to make badminton, but cannot be put into down jackets.

The ancient Chinese knew about the warmth-keeping effect of bird feathers. There was a kind of simple inn called the "chicken feather inn" where there were no beddings, so people used chicken feathers to keep warm.

In 889 AD, Liu Xun, a Tang Dynasty man, served as Sima of Guangzhou. He was from Xiong County, Hebei Province. He found many things in the local area strange, so he wrote "Lingbiao Luyi", in which he recorded: "The chieftains in the south often choose fine goose feathers, sandwich them with cloth, make them into quilts, and then fold them vertically and horizontally. Their softness is as good as cotton wool. It is said that goose feathers are soft and warm but cold in nature, and are suitable for covering babies to prevent epilepsy." In short, goose feather quilts are warm and soft, and children can sleep well under them.

Who invented the down jacket?

In 1920, American Eddie Bauer opened a small shop in Seattle, named after himself. In 1935, he almost froze to death while fishing in winter. He remembered that his uncle had fought in Russia and the soldiers there would stuff duck and goose down into their clothes to keep warm. So in 1936, he designed the world's first down jacket, the Skyliner, and applied for a patent four years later.

Because this garment was rather ugly, only the military, outdoor sports enthusiasts, and people who worked outdoors for a long time would buy it. In addition, down jackets at that time were very easy to shed and had a smell of duck fat, so down jackets became "tool clothes."

It’s worth mentioning that Eddie Bauer climbed Mount Everest in 1963, proving how warm down jackets could be, and the brand still exists today.

Modern high-quality down jackets appeared later. The emergence of coated fabrics in the 1970s allowed the fabric fibers to bond tightly together, thus solving the problem of down shedding.

It was not until the 1980s that down jackets became popular in China. Because the fabrics and processing level were not high, and the appearance was bloated, they were also called "flattering jackets." However, since most down jackets were imported at the time, being able to wear a down jacket was a symbol of status.

Why choose duck and goose feathers?

Waterfowl feathers have a layer of grease on them, so they dry very easily after washing. As a land animal, chicken feathers are harder than duck and goose feathers, and they are not easy to dry after getting wet. They are not as good at keeping out cold as duck feathers, and chickens have less down, so they are more suitable for making feather dusters. Only very low-quality down jackets use chicken feathers.

Nowadays, down jackets are generally made of goose down or processed duck down, because ducks are omnivores and their down has a fishy smell, while geese are herbivores and their down has no peculiar smell. In essence, there is no difference in the warmth-keeping effect between duck down and goose down.

Birds can be divided into precocial and altricial birds according to the growth rate of their chicks. Chickens, ducks, and geese are all precocial birds. They can walk soon after birth and immediately follow their parents to find food. This is an adaptation to improve their survival rate. However, eagles, swallows, sparrows and other chicks have no or only a few down feathers on their bodies after hatching and need to be raised by their parents. These are all altricial birds and cannot be kept in captivity on a large scale by humans.

Ducks and geese are both members of the Anatidae family of the order Anseriformes. Most domestic ducks are domesticated from mallards and spot-billed ducks in the genus Anatidae. Some of the special-looking ducks, such as the Muscovy duck, are domesticated from the horned duck. The Chinese goose is domesticated from the swan goose, while the European goose is domesticated from the grey goose. Both are in the genus Anser. The lion-headed goose in Guangdong is the largest goose breed in the world. In addition, the swan is not very related to the domestic goose. It belongs to the genus Cygnus, so it cannot be said to be the largest goose.

Because ducks and geese can be raised on a large scale, they are most convenient for making down jackets.

The thicker the down jacket, the warmer it is?

Of course not!

The ways of heat loss are very simple, including conduction, convection and radiation. Down jackets will lock in the air, isolating the conduction of air, which is a poor conductor. The small pieces of air between the down are also not convenient for convection, thus preventing the rapid penetration of cold air and the loss of body temperature.

Therefore, the thicker the down jacket is, the better it is. You can’t just look at the thickness.

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