If you’re going to spend top dollar on a work boot, it helps to understand the anatomy of a boot, and why the individual parts matter. We’ve all heard of the outsole and the insole, but what about the midsole? What is a midsole of a boot and how does it help?
A midsole is the layering of the boot that sits directly in between the insole and the outsole. The midsole provides cushioning to help absorb shock as your boot hits the ground, and also helps add structure and durability under the foot.
The midsole of a boot is often one of the most distinguishable characteristics of premium vs cheap boots. A company who aims to reduce costs will take away extra cushioning from the midsole, knowing to the eye, the boot looks much the same.
Cheap, thin midsoles do a bad of absorbing stress, and although the exterior of a cheap boot may look relatively normal, the shock absorption usually deteriorates very quickly due to insufficient midsole material.
Although most midsoles have similar purposes, the different types of midsoles can greatly affect comfort, durability, and cost. In this article let’s take a closer look at midsoles and how they help.
What is the Midsole of a Boot?
As we discussed above, a midsole is the part of the boot that sits directly in between the insole and the outsole. The midsole helps absorb shock and protects your foot from injury. It also helps, along with a shank, to add structure to the entire sole.
However, to perform its job correctly, boot midsoles need to be durable, flexible, and comfortable. Premium materials like leather are often used, but cheaper boots will opt for a foam or matboard.
What Are the Different Types of Midsoles?
Leather is used as a midsole for premium work boots. Leather is a product that adds cushion in a way that is also durable. Many foam midsoles you see in athletic shoes wouldn’t last a week in a rugged environment.
For hardworking jobs that need something that is BOTH comfortable and durable, leather is often used. But of course, leather isn’t cheap, and the cost of the boot is driven up.
Rubber is another very common midsole material used in premium boots. It, like leather, can be both firm and forgiving, making it durable enough and comfortable enough for hard jobs.
But compared to leather, rubber doesn’t necessarily form to your foot quite as well. Overall, both rubber and leather are quality options.
Cork is comfortable, and good at forming to your foot. But overall, cork is not as durable as rubber or leather.
Because it doesn’t provide as much under-foot protection, it is more commonly found in casual boots. But it also may be used in tandem with leather or rubber in premium work boots to help add extra cushioning.
Some premium work boot companies shy away from using cork because, over time and wear, the cork can begin to fall apart, and may begin to bunch up, causing small bumps to form under the insole.
For casual wear, the amount of stress put on a boot may not lead to cork coming apart in the midsole, but for heavy-duty work boots, this can be a concern, and so some premium boot companies may choose to just go all leather for the midsole.
Foam and Other Materials
Molded EVA (ethylene-vinyl acetate) is a popular material used for midsoles in shoes. It’s lightweight due to its foam-like structure despite being made from two plastics.
Another popular material for midsole construction is polyurethane, which is reasonably durable. TPU foam is another option. Ultimately, these types of midsoles are best used in shoes and not heavy-duty work boots.
Some types of cheap work boots will use a fiberboard or matboard material that feels like thin cardboard. As you can imagine, these types of materials don’t add much comfort or toughness, and don’t last.
It’s also common to find foam midsoles in lightweight work shoes. If you want to see some examples, visit our article about the best low top composite toe shoes.
What Do Cheap Work Boots Use as a Midsole?
As I said earlier in the article, one of the tricky things about the midsole is you can’t see it. This means, unfortunately, the midsole is one of the first parts of a boot to be neglected when a company strives to reduce material costs.
There are a few different combinations of materials that may be used for the midsole of cheap work boots. Some companies may use a cheap fiberboard base with a thin layer of foam on top.
That foam will wear down pretty quickly, and after only a few months of use, it will give you next to no shock absorption. But even worse, some cheap boots may simply use a matboard, which feels basically like thin cardboard.
Cheap work boots can still be useful if you’re on a tight budget and need something to get you through. Just remember, you’ll likely need to buy a new pair every 6-12 months, or just suffer through the foot pain.
What Do Premium Work Boots Use as a Midsole?
You will most often find leather used as the midsole for premium work boots. But beware, the price of some of these boots may drive up past $500.
Leather is desirable as a midsole because it is both comfortable and durable. It adds toughness to a boot, but also can form and shape to your foot over time.
And unlike cork, foam, or cheap matboards, leather won’t wear down and lose its structure just in a matter of months. Leather midsoles last, and are therefore a great addition to a premium work boot.
For the middle tier of work boots in-between cheap and premium (let’s say the $150-$300 range) they may use rubber, or some combination of rubber and cork or leather and cork.
Not only does the type of material matter in a sole, but so does the amount of layers. Some premium boots may have over 10 layers between the foot and the ground.
But, in general, most premium work boots will rely on leather as the midsole, combining it with a premium outsole, like a Vibram outsole. For casual boots, it is not uncommon to see a combination of rubber and cork, or leather and cork.
How Does a Midsole Help?
Having a good midsole will determine how long your boots will last and how comfortable you are wearing them. Once the midsole goes, you lose a lot of the shock absorption, and the boot will become very uncomfortable and unpleasant to wear.
Midsoles are an essential part of boots. Their function directly impacts and benefits how long a shoe will last and how comfortable you will be wearing it as well.
If you opt for cheaper boots, buying comfortable inserts might be a good way to add a little bit of comfort. Just like with most things, you pay for what you get in midsoles.