Down Jacket Buying Guide

Normally, we choose clothes based on two criteria: style and quality.

But when we return to the original function of clothing - covering up and keeping warm, our selection criteria will be reversed. For example, in the cold winter, most people will put warmth first when buying down jackets, and style second. Although there is a fact that the styles of down jackets on the market are really terrible, when it is so cold that you are about to have your limbs amputated, the demand for warmth far exceeds the need for shape - of course there are exceptions, and fashionistas often want to look good instead of dying.

When it comes to the warmth of down jackets, it is generally required that down jackets need to indicate the fabric, lining, filling and filling amount.

But unfortunately, we cannot know the warmth of a down jacket without personal experience simply by relying on the above data. So what kind of down jacket data do we need to know the warmth of a down jacket?

Normally, we focus on the ingredients, which contain several key data:

1. Filling; 2. Filling amount; 3. Fluffiness

1. Filling
As the name implies, down jackets are of course filled with down, but in fact, down is divided into duck down and goose down, among which goose down is divided into gray goose down and white goose down. Under normal circumstances, its thermal insulation performance is: gray goose down> white goose down> duck down
Therefore, in order to keep absolutely warm, it is very necessary to pay attention to whether the tag is goose down or duck down when purchasing
But having said that, if you are pursuing cost-effectiveness, you don’t have to consider the issue of which type of down is too much.

2. Filling amount
The filling amount actually refers to the weight of all the down filled in a down jacket. The amount of filling directly affects the warmth of the down jacket. The filling amount of the down jackets we usually wear is usually in the range of 200 grams to 500 grams, and outdoor models can also be seen at around 700 grams.
The down content refers to the proportion of "down" in the down. At present, the down content of outdoor down jackets is generally required to be above 70%, that is, the content of down is 70% and feathers account for 30%. This degree can ensure the necessary fluffiness and warmth of down jackets.
Then you have to ask again, what is the difference between feathers and down? Aren't they always called together?
Down is indeed a general term. It grows on the abdomen of geese and ducks. The reed-shaped ones are called fluff, and the flakes are called feathers.

Yes, feathers are the "feathers" you know, the kind with a rod - just imagine a smaller version of a badminton or feather fan, of course, it is many times smaller and softer. And down looks like more fluffy cotton, which is the main contributor to the warmth function of down jackets.

3. FP Fluffiness
Fluffiness, in English, is "Fill Power or Filling Power", usually referred to as FP, which is directly translated as filling capacity, and can also express its original meaning.
Wikipedia and the International Down and Feather Testing Laboratory and Institute (IDFL) have similar definitions of the term FP, which is the space occupied by a certain weight of down in a specific environment, and the classification is based on this. FP is just the volume of a constant weight of down under a specific environment. To put it bluntly, fluffiness is volume, and volume is fluffiness.

Get an intuitive feeling
Fluffiness is generally divided into 550, 600, 700, 800 and 900 FP. It usually refers to the value of the volume cubic inch occupied by one ounce (30 grams) of down under certain conditions. For example, if the space occupied by one ounce of down is 550 cubic inches, the fluffiness of the down is called 550 FP.
However, according to the data, duck down quilts first appeared in 1892, but there was no concept of FP at that time, and even decades ago, there was no concept of FP. At most, it was marked as "premium goose down" to emphasize how professional you are.
To be honest, a more intuitive comparison may be the thickness of the product. Usually when we compare two down jackets, the simplest and most direct comparison is to look at the thickness of the down jacket, which one is thicker and which one is more reliable.

But can a simple thickness comparison really indicate the quality of a down jacket?

First, let's look at the principle of warmth preservation of down jackets: down is an animal protein fiber, and the tens of millions of triangular tiny pores on the ball-shaped fibers of down can shrink and expand with the temperature changes, producing a thermostatic function, which can absorb the flowing heat emitted by the human body and isolate the invasion of cold air from the outside, thereby producing a warming effect. In simple terms, it absorbs human body heat and forms an insulating layer. The more fixed air in the insulation layer, the better the thermal insulation performance.

Knowing the principle, let's briefly analyze why the higher the fluffiness, the better the thermal insulation performance. The size of the thermal insulation layer determines the thermal insulation performance, and the size of the thermal insulation layer depends on the fixed air volume of the down. For example, if we need 1800 cubic inches of down, the down required for 600 FP and 900 FP is 3 ounces and 2 ounces respectively. The fixed air volume is the same, and the warmth effect is the same, but using 900 FP can be lighter, which is why many outdoor brands' down jackets are very light and thin.

In addition, the fluffiness is related to the proportion of down in the down and the average size of the down clusters. Goose down is fluffier than duck down. The down content of goose down can reach 95% and the fluffiness can reach 700 FP. For duck down of similar quality, the down content can reach 90% and the fluffiness can reach 600 FP. The price of down with a fluffiness of 700 FP is about 3 times that of down with a fluffiness of 600 FP. Down with a fluffiness of 800 FP costs more than three times that of down with a fluffiness of 700 FP, and down with a fluffiness of 900 costs more than 10 times that of down with a fluffiness of 700 FP.

Left: duck down; right: goose down. Take a closer look. Do you find any difference?

Unfortunately, my country does not require down jackets to be marked with fluffiness when they leave the factory. Although there will be fluffiness values ​​during quality inspection, I have asked many salesmen, and 90% of them know nothing about it, and they don’t even know that there is a concept of fluffiness.

However, it is not entirely true that emphasizing FP is reliable.
In terms of warmth retention, of course, the higher the fluffiness, the better. As mentioned above, the larger the volume, the better the corresponding thermal insulation effect. However, the larger the volume, the smaller the spatial density will be for a constant weight of down, and the support of the down will also be lower and lower because it provides more space. Down cannot exist alone as a thermal insulation layer. Without sufficient support from other materials and during use, the most vulnerable part of down is its fluffiness.

This really proves the old saying - don't go to extremes in everything: low fluffiness has the best pressure resistance, but the thermal insulation performance is too weak, high fluffiness has the worst pressure resistance, but the thermal insulation performance is very high. It is better to return to the golden mean and choose a moderate fluffiness that can resist pressure and keep warm.

To sum up, the above is a lot of nonsense:

1. In terms of the thermal insulation performance of the material, gray goose down> white goose down> duck down.

2. As for fluffiness, unless there are special circumstances, it is completely sufficient to choose 550FP-700FP.

How to choose a down jacket

Let's talk about how to choose a down jacket. Basically, if you follow these points, you can buy a down jacket that is warm, pressure-resistant and not too bulky (and avoid black-hearted cotton):

1. Look at the label:

Understand what the down content, filling amount and filling material are. Look at the fabric: Down jacket fabrics should be down-proof, windproof and breathable, among which down-proof is the most important. I personally prefer to buy down jackets made of T/C fabric.

Here is a popular science. T stands for polyester TERYLENE and C stands for cotton COTTON. The textile industry is accustomed to putting the components that account for a larger proportion in front of the ingredient description, so T/C is polyester-cotton fabric with polyester accounting for the main proportion.

2. Touch the down jacket with your hands.

If you can feel a lot of hair stems, the down content is low and the feather content is high. If you can't feel the hair stem, it may be because of flying silk. At this time, rub it through the down jacket. If it is difficult to rub it apart, then the filling is down. If it rubs apart quickly, it is likely to be "flying silk", that is, some inferior fake down, usually the scraps of duck and goose feathers are crushed into velvet, and some do not contain "down" at all.

3. To judge the fluffiness of a down jacket, you can fold the clothes, empty the air, and compress the clothes to the smallest state.

If the clothes can return to their original state in a short time, it means that the fluffiness is high and the down content is high. If it takes a long time to return to its original state, or it is difficult to return to its original state, it is obviously low in down content and low in fluffiness.