What is down loft?: The Ultimate Guide To Fill Power Skip to content
What is down loft?: The Ultimate Guide To Fill Power

What is down loft?: The Ultimate Guide To Fill Power

If you’ve ever spent any time shopping or researching goose down products, you’ve probably come across the term “loft” or “fill power”, but what exactly does it mean, and why does it matter? Essentially it is a rating system for down. It stands as a universal measurement for customers to gauge sufficient quality and the insulating potential of their down purchase. In this article we will explore what loft is, how it is measured, and why it’s such an important factor in virtually every down product. From jackets or sleeping bags to luxury pillows and duvets, loft matters!


What is Fill Power?

Down loft is often referred to as “fill power” which is a great term for it because it helps us to understand what it is. How much space can a specific amount of down plumules (or clusters) fill? Its “power”, or ability to take up space, is its “fill power”. To put it simply, the higher the loft number, the better. There is a bit more to it than that, but now we have a basic understanding of what that loft number means when you’re purchasing your next goose down pillow or comforter.


The Nature of Down Loft

If you’ve ever looked closely at a down cluster, it is quite a magical thing. It almost appears to be alive in the way it moves. It looks like it might just be the lightest, fluffiest thing on Earth. Well, it kind of is! As captivating and magical as a single plumule of down can be, the real magic happens when tens of thousands of these little guys get together. When this happens, the clusters gently cling together and air is trapped in amongst their millions of tiny filaments. Now we have the ultimate, ultralight insulating material, and its fill power, or loft, will tell us just how much insulating potential it has.


Different types of down, of course, have different fill powers. There are many varieties of goose down found throughout the world. Some are sourced ethically and sustainably and some are not, which is something you should always be aware of when purchasing down bedding. With such a variety of different geese, and maturity being a factor as well, down loft can vary greatly from one source to the next. The best down products are those, like St Genève duvets and pillows, made with materials sourced from a reliable and sustainable supply chain, so you can be sure the quality is consistent and the loft is always as advertised.


an example of down loft fill power


How is down loft or fill power measured?

There is a universally standardized process for determining the loft of down. It’s actually a fairly simple process but it must be done carefully, in a controlled environment, by experts who are certified to do so. It starts with weighing out an exact amount of the down being tested, usually one ounce. The down is then put into a glass cylinder. If you were to place two cylinders beside each other, each with a different quality of down, you would notice a difference in the height of the down in the cylinders. A cylinder with one ounce of 800 loft down would reach much higher than one ounce of 400 loft. It’s the same amount of down, by weight, but the higher the loft, the more space that one ounce can fill up. This is quite obvious to the naked eye when comparing high quality down to low, but to determine the actual loft number, there is one more step. A precisely weighted disc is placed in the cylinder, which compresses the down. The height of this disc is then measured to determine the number of cubic inches one ounce of down takes up. This number is what gives us the loft, or fill power, of the down. The highest fill power possible is 1000 loft, which is what is used in the St Genève Embassy pillows and duvets. They are made with the highest quality white goose down in the world.


Why is high loft down better?

As you can imagine, a pillow or duvet filled with a high loft down is going to have much more resilience, be much puffier, supportive, and a more versatile insulator. The high loft allows it to be more efficient, in every way, while being lighter in weight, giving it the highest possible volume with the lowest possible density. This is why fill power is so important and why high loft down is so greatly sought after around the world. A higher loft also helps the down to maintain its firmness and structural integrity. High loft down can be compressed over and over and over again. It will always bounce back, therefore increasing the longevity of your goose down bedding. Low loft down tends to be brittle and breaks down over time.


What is the right loft for you? 

Well, that entirely depends on your budget and the type of investment you’re wanting to make in your comfort. Typically the higher the loft, the higher the price, so as with most things, if you want the highest quality, you’re going to pay more. Down bedding is an investment that can last many many years. If cared for properly, a high quality down comforter can last a lifetime. If quality, comfort and durability are important to you, you’ll want to invest in high loft bedding.


A Guide to Down Loft & Fill Power Quality


Here are some examples of what quality of down bedding you can expect based on fill power:

 300 - 450 Loft  Department store quality
 500 - 600 Loft  Good quality products
 650 - 850 Loft  Exceptionally high quality products
 900 - 1000 Loft  Most elite quality products available


Purchase the right goose down pillow and duvet

Knowing what down loft fill power is and how it’s calculated is going to give you much more confidence when purchasing your luxury bedding. As long as you’re purchasing from a trustworthy and reputable company, you can use fill power as your gauge for quality. It’s as simple as choosing the highest loft within your budget. Be sure to check that the company you’re purchasing from has the appropriate certifications, to ensure authenticity. We hope that if you are in the market for luxury bedding, you will have a look at the beautiful selection of goose down pillows and duvets we have available in our store. With fill powers ranging from 670, all the way up to the prestigious 1000 loft Embassy down, we know you will find the perfect luxury duvet and pillow for you. Visit our store today!

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