New shoes or boots can be too tight, causing pain and increasing the likelihood and severity of bunions and ingrowing toenails, etc. It is therefore very important to make sure that you purchase the right size and type of shoe for your feet. However, most shoe leather can be softened or stretched a little bit to relieve some of the discomfort.
Leather uppers are made of solid, thick cowhide leather. Therefore, there is only limited scope for softening and gaining more surface area by stretching. When viewed under a microscope, it can be observed that leather is a braid of multiple fibres. One gram of leather has an internal surface area of up to 300 m², mainly as its fine fibres are strongly interlocked. Hence, leather has a high resistance to tearing and bending.
Leather in cross-section. The fibre structure is extremely dense and therefore stable.
Stretching shoes and liquid shoe stretch sprays
Tanners and shoemakers use various tools and methods to make leather more flexible or softer.
The braid of fibres can be loosened by stretching. The tanner does this by using a staking machine. The shoemaker has several options. By using machinery, tools and knocking, the fibre structures are stretched or torn microscopically, causing the leather to become softer and gain some surface. Getting this done professionally ensures that the necessary stability of the leather is maintained.
In addition, moistening the leather also helps to stretch it. Moistening the leather softens and swells the fibre braid, allowing the leather to deform more easily and more permanently.
A shoemaker explains how to stretch leather shoes and boots.
Therefore, there are several ways to make shoe leather softer:
With shoes than only pinch slightly, it is best to walk about in them for an hour and try again. Wear thick socks to support the stretching. But not too thick. Otherwise the leather could be overstretched and the shoe becomes too big.
Wearing slightly wet socks is often recommended. The slight moisture ensures the leather is additionally pre-softened making it easier to deform. But beware! Too much moisture can cause stains!
Shoes can be painfully tight.
There are many myths about "moistening". For example, it is recommended to "pee" into the shoes or boots. Many shoe forums recommend alcohol, shoe shine sprays from specialist retailers, special oils and many other liquids. The rumour that urine is particularly good is wrong. Any kind of moisture makes leather softer. "Water" would always be better than urine. Alcohol is not suitable at all because fats in the leather get dissolved by alcohol and the leather loses its suppleness.
Never use extreme heat to dry! Do not put wet shoes on the radiator. High temperatures cause the fibre braid to stick and the leather becomes hard and can shrink. The fibre braid can then only be loosened again with extreme force, which can also damage the structure.
A relatively new method involves placing a plastic bag full of water in the shoe and then putting it in the freezer. The water expands as it freezes, exerting strong pressure on the shoe. This idea is mainly recommended from online mail order businesses wanting to significantly reduce their return rate.
Stretching of shoes using the freezing method.
The described methods only work when the leather is not too tight. Definitely too tight shoes or with completely wrong fit cannot be saved. Then the leather can even tear through the use of force to make it softer and expand. Heat should not be used because too high a heat shrinks leather.