When you are looking online at all the backpacks available you will often find yourself reading the specs. I know, they are probably putting you to sleep while you sit in bed with your iPad, but bear with me.
The volume of your pack, the features and the overall weight are important, and easy to understand.
But what about the backpack material? Kind of confusing, right?
I had the same problem, and I was sick and tired of wondering what all these materials are, and what the difference is.
So, I took the pain out of understanding backpack materials and collected all the information in one place for you.
Note: If you have a specific question, it might be easier to jump right to the section via the menu below.
One of the most important questions when it comes to backpacks is: what is it made of. This means, what is the main material that the pack is made of. There are four main materials in modern backpacks and they can be broken down as follows:
Nylon is one of the most popular and often seen materials used in backpacks today. It is actually a broad range of plastics (Polyamids) that can be melted down and turned into various things including fibres. It is these fibres that are woven and used for backpacks.
One of the reasons, apart from being able to be woven, that Nylon is so popular for backpacks is that it is strong, durable and can resist abrasion and temperatures very well. You might also be surprised to learn that it can resist various insects and other common backpack issues like mould, which is yet another reason you see it used absolutely everywhere.
Nylon does have one weakness compared to Polyester (below) though, and that is UV. Polyester withstands UV far better than Nylon.
Note: More on the specific weaves, weights and designation of these fibres further down.
Similarly popular, especially since the 70s when it was used in way too many clothes, Polyester is another plastic based fabric that is super durable and wear resistant as well as not reacting to many chemicals and drying very quickly. It also does not wrinkle easily and is strong and lightweight. Phew, that is a lot of great properties.
It is probably one of the most popular materials used in backpacks, depending on the brand.
Not found as often in backpacks, Polypropylene is still a great plastic for so many reasons: it can be easily melted and remoulded despite having a high melting point, is very resistant to water and other chemicals and is very strong and tear resistant. It also takes a lot to wear this plastic out.
Despite this, you will only find Polypropylene in very specific applications or as a complete material in more low-end backpacks and bags.
A very old school materials that reminds you of bags or backpacks your parents used to carry. Despite this, it has made a comeback with more fashionable brands like Hershel and Fjallraven, as well as other brands where weight is not so much of an issue (because they are not used for hiking, camping etc).
Originally Canvas was always made of cotton, and quiet heavy as a result. These days it can be made from a variety of fibers, which may be a little lighter. It is typically still quite heavy, but it's durable and will usually last a long time.
Many manufacturers will give their materials specific names or designations to make them stand out. Despite this, they are usually all based on the same materials I have outlined above. The following are the most popular of these materials, many you have probably seen in backpack descriptions.
It sounds impressive, right? Material that just can't be ripped!
And it is certainly stronger than other versions of each material. Ripstop Nylon is probably the one you see the most, but Ripstop is a general term used to mean that the fiber has a special kind of weave. Interwoven within the normal weave is a thicker, stronger fiber, placed at specific intervals. This helps make the fabric stronger and more wear resistant overall and has the unique ability to stop small tears from spreading in the fabric.
Ripstop is most commonly used in very tough applications like sails, hot air balloons and camping gear, but you will see it in some areas of backpacks.
These days Cordura is a complete brand with a portflio of Cordura materials that cover a wide spectrum of applications. It all started though with a single 1000D Nylon thread created using a specific air-jet process. The result was very strong and durable Nylon thread that Jansport went on to use in their backpacks back in the 1970s.
Today, their fabrics consist of a range of durable Polyester and Nylon products that are trusted by many brands and military branches around the world. So, when you see Cordura mentioned in a backpack material, you know you are getting a quality material.
These days Kodra seems to be mainly produced by a variety of Asian manufacturers, so is not as tightly controlled as Cordura. However, it is considered to be very abrasion resistant just like Cordura is.
If this sounds like something you should use in the military, you would be right! DuPont originally developed Ballistic Nylon back in World War II as a material to help product soldiers from shrapnel. Unfortunately it was not as effective as they had hoped, and has since been replaced by Kevlar vests and other more modern "bullet proof" options.
However, in the process of solving this problem they developed a very strong and durable material: Ballistic Nylon. It is basically a piece of woven Nylon fabric that has a very specific weave that makes it stiffer and more wear resistant than normal Nylon. The typical weave is 2x2, which means two yarns of thread are woven in each direction instead of one. There are lots of variants around though.
The original was also a 1050D material, but again things have changed and you will see lots of variety on the market.
The only thing to keep in mind is that when Ballistic Nylon is mentioned, you know it is a very wear-resistant material that will last for a long time.
Now you are well versed in the materials used in backpacks, it is time to dive into the specifics. Strength and durability.
In most cases you will see a whole lot of letters and numbers associated with the material your backpack is being made with, such as:
And many other variations. In this section I will try to quickly and simply breakdown what it all means.
The first and most important part is the number with the D at the end. The D refers to Denier and is a rather complex sounding measurement of how heavy a length of materials is. It is calculated based on a specific length (9000m) of yarn. But, in reality what it means is this:
A higher Denier means a heavier overall fiber. If you are comparing the same kind of material, a heavier fiber will normally also mean that it is stronger.
For example: a 1050D Nylon is stronger than a 650D Nylon, all things being equal.
However, if you are comparing Polyester against Nylon or even Cordura against standard Nylon, things can vary a lot.
Also be aware that some manufacturers use coatings, backings and different weaves to increase the strength and abrasion resistance of the material. This post shows you the relative (tensile) strength of various materials, and demonstrates how various types of fabrics can vary in strength.
Not as often seen in the high-end backpack world, but still used with fabrics in general, Thread Count is an alternative to Denier when it comes to measuring fabric weight. It is a count of how many threads there are in a square inch. Again, a higher number generally means a stronger fabric.
The third alternative is based on the metric measurement of density - grams per square meter (which would be something like ounces per square inch in imperial). It is most often seen with Polypropylene and other fabrics where no weave is used, so thread weight or thread count is not as relevant.
When you get a little down and dirty with various types of backpack materials, it pays to compare their actual strength on a weight for weight basis. That is where the so called "Tenacity" of the material comes in.
Most of you won't be concerned with this measurement, as it is rarely available in backpack specs. However, it is worth noting that:
Making a backpack 100% waterproof is difficult due to the stitching, zippers and openings.
However, a lot of manufacturers add layers or coatings to their packs to help keep them dry.
The following is an explanation of some of the most widely used waterproofing materials.
Probably the most often seen letters when it comes to waterproofing. DWR is a coating that is added on the outside of materials to help keep water at bay.
The problem with DWR is that it slowly deteriorates over time due to abrasion, dirt, sun and other factors. So, although the water may bead when you first get your pack, slowly this effect reduces until it starts to soak. This is where the next line of defense comes in - the material or the backing.
Another alternative is to re-coat your pack with DWR, or prevent it from deteriorating in the first place by keeping it clean and salt-free, as well as storing it in a dark, cool, and moisture-free place.
An alternative to the standard DWR is to have a PU (Polyurethane) coating on the material to help waterproof it. So, you might see the initials PU mentioned in the specs after the material name (eg. Nylon 500D PU).
Another material that is sometimes seen in waterproofing efforts on backpacks is good ol' PVC (Polyvinyl Chlorid). More often associated with your drainpipes at home, this can also be used in smaller quantities to help with this process.
One of the most commonly seen interior layers on waterproof packs is the TPU - Thermoplastic Polyurethane Film. Depending on the manufacturer's use of the material as well as the quality of the layer, it can be quite effective, especially when combined with DWR on the outside.