Wooden (old), metal and beech wood skewers.
The term last refers initially to the "template" on which the upper (leather) will be assembled to give the final volume and shape of the shoe.

Figure 1: Wooden form
Initially made of wood, the forms were soon industrialised in plastic...

Figure 2: Example of leather assembly on the form (here green)
In the very high-end or even bespoke world, shoe trees are often included with the shoes and are "form-fitted", i.e. they correspond exactly to the shape used during assembly in order to perfectly maintain the volume.
2. Why and when to use it?
When you wear your leather shoes, your feet naturally sweat. This is inevitable. The leather will absorb this moisture. Also, when you walk, your shoes bend in different places, especially at the metatarsophalangeal joint. These folds, which are called walking folds or ease folds, will mark the leather in the areas that are most stressed during wear.

Figure 3: Worn shoe without shoe trees
It is therefore advisable to place shoe trees as soon as you remove your shoes so that the moisture is absorbed (provided that your shoe trees are made of raw wood). In addition, these will tighten your shoes so that they regain their initial last in order to avoid walking creases as much as possible. However, it's necessary to bear in mind that creases are inevitable.

Figure 4: Worn shoe with shoe trees
3. How to choose shoe trees?
There's a wide variety of shoe trees. They are made of plastic or wood, each serving a specific purpose.
Plastic (or "openwork" metal) shoe trees are generally used for travel or more generally for transport because they are lighter than wooden ones. However, their absorption capacity is non-existent. We therefore advise against their long-term use, as they do not fulfil their main purpose.
As far as wooden shoe trees are concerned, there are several types: beech wood or cedar wood. Each has a similar absorption capacity and is easy to use. However, they will be heavier than their plastic counterparts.
To ensure that the shoe tree fits your shoe size, make sure that it stretches the leather well at the joint (see Figure 5) and that it is not too tight at the back to avoid over-deforming the counter (see Figure 6).

Figure 5: The leather is stretched at the metatarsophalangeal joint

Figure 6: Here you can see that there is still some space between the back and front of the shoe tree.
(TIP: Give the shoe tree a quick tap on the buttress to release it if it's stuck.)
Q&A
In order to limit the wear of the leather in the walking creases and to absorb moisture.
- Which material to choose?
It's best to choose wooden shoe trees. However, plastic or metal shoe trees for a trip are fine.
We have to put on the shoe trees as soon as we take off our shoes. No need to wait!
- Is it necessary to have one pair of shoe trees per pair of shoes?
This is preferable but not necessary! You can alternate one pair of shoe trees for two pairs of shoes if you have a rotation.
- Is it necessary to use "form" trees?
Again, this is preferable in an ideal world. However, it's very rare, except in bespoke work. So a pair of generalist-form shoe trees will do just fine.
- Do we have to put on shoe trees when our shoes get wet?
Absolutely! They will help to absorb moisture.
The 7L shoe trees
We have finished the development of our new shoe trees! They are now available in our Parisian shops and online (it's here!).
Our shoe trees are made of solid beech wood with a rough finish to absorb moisture and keep the shoes in shape. The forefoot is made up of two parts connected by springs, allowing the wood to adapt perfectly to the dimensions of the shoe, and thus to fulfil its role.
A new shape: the "7L" shape. A unique design: these trees have been designed to fit our different shapes perfectly. The instep has been slightly raised and we have taken care to keep the spring system at the front.
7L Shoe tress
New design !
Beech wood
39€