Leather has unique properties that enable it to be used to make sumptuous objects (shoes, accessories, clothing). Through this dossier, (re)discover all the know-how linked to this exceptional material, from the selection of the skins to the final finishing of the patina and the tanning process.
It is one of the noblest materials you can find. Textured or smooth, vivid or sober, glossy or matt... Leather allows the craftsmen of yesterday and today to fashion the most beautiful objects, and offers the wearer a plethora of qualities that we will discuss in these lines.
First of all, it should be noted that leather is not a material like any other because of its animal origin. Although history shows that humans have also known how to work with vegetable materials to make various types of shoes, they nevertheless have a clear preference for skins, particularly in Western societies. The robustness and durability of this material are used to make solid shoes with infinite aesthetic variations.
The primacy of countries such as France, Italy and the United Kingdom in leatherworking is acknowledged, which explains their overwhelming presence following the "Made in" label on most luxury items made from this material. There is no dogma in this statement, for there is no doubt that the world is full of passionate and expert craftsmen, some of them anonymous... But once again, history bears witness to this European predominance in the field that interests us in this case.
To conclude this introduction, we wanted to mention the ethical and environmental aspects of leather use. Rather than avoiding the issue, or beating about the bush, we feel it is more honest to put our foot down, as the questions are quite legitimate.
Yes, leather is a skin, and its treatment is polluting depending on the methods used. So no, its use is not neutral, whatever the angle chosen to address this issue. But our conviction is also based on a passion for what lasts and is passed on. Therefore, based on the premise that top quality leather is only obtained from an animal that has been well fed and treated throughout its life, and that it is an extremely durable material over time, we believe that a pair of genuine leather shoes purchased with the intention of being worn for years is preferable to purchasing pairs of inferior quality or synthetic materials that will never match the lifespan of a product made of leather.
This is without even mentioning the fact that the manufacture of certain synthetic materials can be questionable both ethically (Origin of the material? Working conditions? Toxicity?) and environmentally (Exploitation of non renewable resources? Pollution linked to the substances used? End of life cycle of the product?).
It goes without saying that in the context of the second-hand market, the presence of leather appears all the more relevant as ethical and environmental considerations are changing completely. A product that has already been manufactured, that has been restored, generates a lesser impact... Without altering the aesthetic, practical or technical considerations.
These elements are, of course, debatable and are not intended to be a universal truth... But we wish to maintain an authentic, sincere and passionate approach to our profession, which leads us to share our vision in all honesty.
But it is now time to get to the heart of the matter in order to share our knowledge and expertise on this unique material, leather... even though it includes a very wide variety of skins. To begin with, we will see how they are sorted, selected and tanned.
Secondly, we will look at the different types of leather and finishes in order to understand the specificities of each.
Finally, both for pleasure and necessity, we will discuss those details and finishes that make the most beautiful leathers and shoes.
1 In the beginning: the selection of the hides and the different stages of tanning.
"Making leather involves a multitude of steps and methods... with varying qualities in the end. The material is becoming scarce... unless it is the demand that is constantly increasing, creating a certain de facto scarcity of the material. By way of a brief explanation, let's remember that twenty years ago, luxury was neither a sector nor an industry, it was a niche. Although Arnault and Pinault had already started to buy up and optimise in all directions, luxury was still dominated by houses in which the designers were in control.
Today, the hyper-industrialisation of brands has generated a change in strategy: the passion for creation and work well done have often been relegated to the background, overtaken by the race for turnover growth and margins. As a result, production volumes have increased considerably, and where there were only two collections per year 15 years ago, some "luxury" brands now deliver up to 12 collections per year.
More demand, therefore... But not necessarily the capacity and know-how to meet it. We could mention these ethical, environmental and aesthetic horrors from Bangladesh or Pakistan... But to say that this type of material is already disturbing to the eye is quite enough.
In this competitive context, French or Italian tanneries (calves and other cattle) and megisseries (lambs, sheep, etc.) with recognised know-how have often been bought up by major brands wishing to secure their supplies and ensure control of the quality of their skins. LVMH bought the Roux tannery in Romans, while Hermès bought the Annonay tannery in Ardèche. The best quality leathers are being snapped up at a high price (or leather), which makes it more difficult for the still independent houses and small bootmakers to obtain top quality leather. Just before we look at how this coveted leather is obtained, let's go back to the origins of a quality hide.
The origins of beautiful leather lie in beautiful animals.
Let's go back to something we mentioned earlier: a beautiful leather is above all a beautiful skin. Scratches, bites and punctures are defects, and an animal parked in a shed with hundreds of its fellow creatures cannot offer the immaculate leather that we appreciate so much. The prerequisite is therefore a "happy" animal, well fed and away from any barbed wire. Stress is also a factor that can affect the quality of the hide.
In fact, some people may have already realised that just as skin and hair tell us a lot about the quality of a human's life, so leather and fur tell us a lot about an animal's life. In Europe, "leather animals" are also quality "meat animals".
After the inevitable killing of the animal, the skin is removed and the superfluous elements (hair, fat...) are removed during the river work stage. But the one we are particularly interested in, the one that will freeze the beauty of the hide for eternity or almost, is called tanning.
"Freezing" the hide to make leather: the tanning stage... or tannages
In concrete terms, this consists of immersing the material in various more or less cleansing substances. In fact, we should speak of "tanning" in the plural, because there are two types, depending on whether the origin of the tannins is chemical or vegetable.
Mineral tanning
This is carried out using chemical tannins (including chromium salts) and has several advantages: it is quicker to carry out than its vegetable counterpart and produces a robust leather. Dyeing is made easier by the possibility of using chemical dyes, which increases the range of colour possibilities. Box calf, which will be discussed below, is obtained using this tanning method.
On the other hand, it is a polluting process, and particularly toxic for those who carry it out. I mentioned Bangladesh earlier: we have seen images of teenagers wading through baths of chromium salts to stir the leather, which is extremely dangerous. Also, coming back to the material itself, chrome leather is quite stiff.
Vegetable tanning
The approach here is different, although the process is relatively similar to mineral tanning. It is the tannins and therefore the substances used that will vary, the former being here of...vegetable origin (you could see it coming from afar). This treatment is gentler, but also longer than the first and more expensive, and is generally reserved for the most beautiful skins whose natural feel and appearance will be preserved. This explains why a company like Hermès favours this type of tanning and why this type of skin is not found (with some exceptions) in the lower end of the market.
Let's be clear: regardless of the method used, the leather can be of very high quality. Mineral tanning, however, owes its popularity in the world of quality footwear to the texture rendering that favours dyeing work and the robustness provided to the leather, while the touch and suppleness of vegetable-tanned hides are more appreciated for certain leather goods or ready-to-wear products.
This was the most technical stage of leather working. Let us now look at the different types of leather that can be found.
2 The different varieties and finishes of hides and their properties.
As we have said, hides vary in quality. The aim of this second section is to learn more about the varieties of leather that can be found on the market. Before going into the details of the different varieties used, we will look at the different thicknesses and layers of leather.
Full grain, corrected grain... Lexical point.
We mentioned tanning earlier, but it is important to know that not all hides are treated in the same way with regard to the preservation or otherwise of their different layers. Three categories of leather can be roughly distinguished:
- Full grain aniline leather (or dipped leather) retains all the layers of a hide which must be of excellent quality and without defect. It will simply be dyed in the mass and dipped (!) in a pigment bath, sometimes with just a light transparent finish. Nappa is very close to this finish, except that it is a little bit more protected than the dipped one can be.
This type of treatment is mainly used in ready-to-wear and sometimes in leather goods, because it is very often made from lamb or goat in order to enhance their fineness and suppleness... Qualities that are less interesting in the world of shoes, as you now know.
- Corrected grain leather and split leather are of inferior quality, as the top layer has defects and will be removed. But to keep the appearance uniform, a coloured coating will be applied to the surface. The appearance is obviously much less natural.
- The bookbinded leather is the least noble of the finishes, since the upper parts of a too damaged skin are removed and then covered with a very thick coating. It is, so to speak, almost no longer leather since it disappears under a thick plasticized veil... No interest, this photo speaks for itself...
Alongside this, there are nubuck and suede leathers, which are characteristic because of their...velvet feel. The former often offers a finer velvety feel and is made with a good quality hide, while velvet is a little less noble: instead of being sanded on the grain side, it is turned over so that the flesh side, which has no defects, is visible.
Finally, the use and finish will depend above all on the type of leather and its properties, which we will now see.
Calf, lamb, deer, goat... Recognise the different leathers and their quality.
Discussing the different varieties of leather will be an opportunity to understand what makes it possible to estimate their quality and to distinguish them.
Calfskin, the undisputed star of the shoe.
Relatively supple but solid, fine-grained, robust: calf has much to please. It is the material that makes up the vast majority of shoes that we come across, as the properties mentioned are particularly relevant to the manufacture and use of footwear.
Depending on the finish, it is possible to judge the nobility of the leather by eye and touch. A top-of-the-range boxcalf will first of all have a very deep colour, sometimes with a few shades depending on the patina, and a fine, smooth, often shiny texture. This fine grain is perceived by a very pleasant, almost satiny feel to the touch. When finished in nubuck, the calf has a very beautiful colour, also deep, and a perfectly uniform and fine aspect which will be felt by a very regular peach skin effect.
The defects that can be found on this type of leather are mainly the presence of veins and other imperfections, or rather unsightly cracks or deep folds. On the other hand, if the quality is there from the start, your piece of calf leather will stand the test of time. It has an extremely good patina and can tolerate colour changes without any problems, should the colour fade. Even after decades of oblivion, certain leather goods in particular come back to us with a spectacular shine.
Lamb: soft, supple & strong.
Appreciated for its great suppleness and durability, it is particularly present in ready-to-wear, glove-making and, to a lesser extent, in leather goods and shoes. Its grain is extremely fine, and its touch when dipped or nappa is absolutely extraordinary, calf being a little drier. To pass your hand over this leather is the best way to estimate its nobility, your senses will not deceive you...
Those who wish to experience it and "get their hands on it" are invited to go to the glove department of a department store or a fine brand and touch the product. The silk satin feel is striking. It is used less in shoes because its suppleness is not necessarily suitable, as has been said, although it is very strong.
Like calf, it will develop a beautiful patina, although it may lose some of its suppleness and softness of hand over time. It is quite possible to moisturise it and, once again, to rework the colour if necessary: lamb can withstand the years.
Goat, the finest of skins.
Less frequently used than lamb and veal, goat is nonetheless very interesting. It is simply that its extreme fineness and suppleness limit its possible uses somewhat, although some people do not hesitate to take up the challenge!
No doubt you have already come across a jacket in nubuck goat leather, as soft as suede and as fluid as silk satin... It is true that in ready-to-wear, the use of this material is unanimous for its proximity in terms of fall with a fabric. It is not uncommon to come across smooth goat leather in leather goods, whereas in the world of shoes, it is limited to a few appearances and in the women's wardrobe for the most part: very supple loafers uppers, braided sandal straps, etc. In terms of quality, we are going to approach the criteria of lambskin, i.e. regular grain, and a fine velvety texture without veins for nubuck and suede finishes.
Deer and its inimitable texture.
Rare, precious and discreet at the same time, deer leather (very close to reindeer) is a truly magnificent skin with a well marked grain. It is regrettable that it is rarely used, particularly because of its high cost and the "rarity" of the animal, as its great robustness and suppleness delight enthusiasts. Thicker than its counterparts, deer leather can be used for coats or jackets, bags and also for shoes, although it is rarely used for the latter category and almost exclusively for loafers.
In terms of quality, it seems unlikely that you will come across poor quality deer leather. This is because it is only found in the high end of the market and is expensive to manufacture. In any case, you have to be a connoisseur to be able to tell a grained calf from a deer, as most expert customers are in the higher end of the market rather than the entry level.
But all the quality and nobility lies in that absolutely inimitable, soft touch, with that particular bounce. It is a very pleasant skin to handle, and the exceptional way in which the folds are marked and then disappear as soon as the skin tightens up is worth a look.
To finish this article "in beauty" if I may say so, a short diversions to the leather mirror shining and waxing workshop, the final stage in the sublimation of this very noble material.
3 For pleasure: stains, patinas, mirror shine... Those final finishes that make the difference.
It is not the purpose of these lines to go into the details of the different methods and know-how concerning the patina of a leather, its mirror shining etc: this will be the subject of a future paper. On the other hand, it seems interesting to transmit to the reader in search of expertise some elements concerning these ultimate and splendid finishes. We will deal here mainly with the case of shoes, although it is possible to use certain techniques discussed in the world of leather goods or ready-to-wear. We will start with the dyeing of leather and then with the mirror shine of shoes.
The art of leather dyeing....
By nature, leather has a greyish or light colour which will of course have to be dyed. This is known as "crust calf", an undyed calf leather. This can be done by various methods (usually alcohol dyeing, water dyeing or acrylic dyeing). It is really this stage that will bring all its brightness to the leather as well as... its colour.
It is often done with a brush, sponge, cotton or with the fingers in several times. The craftsman deposits the dye on the leather which will either absorb it or keep it on the surface depending on the technique used. After a drying period, the operation can be repeated several times until the desired colour is obtained. A cream should then be applied to the leather to intensify and even out the colour, a step known as "creaming" which will also be carried out during regular maintenance. Illustration in video!
In the same way that there are several qualities of leather, there are also several qualities of dye. The care taken in the work, the mastery of the know-how and more generally the passion of the craftsman for his trade are essential. These elements are not material, not "palpable", nor measurable, and it is not always easy to talk directly to the person who dyed or maintained the shoes. When possible, do not hesitate to discuss with him/her, and trust your feelings during this discussion!
To go into more concrete considerations, visually, a quality dye job offers above all deep colours. On black, blue, green or brown tones, there will be a beautiful intensity and subtle reflections. In some cases, a patina will be applied, giving the leather beautiful shades: certain areas will be darker or lighter, and this gives the shoe a certain relief. It also personalizes the piece because of the uniqueness of each brushstroke and the infinite possibilities offered to the customer!
Finally, the last optional step, although often appreciated in the world of classic shoes, is mirror shine.
A beautiful mirror shine to bring nuances of texture to the shoe.
This step, superfluous but very elegant, glosses the leather in order to generate a very intense, almost mirror-like shine. The shoe polish, which is also used to shine and slightly waterproof the rest of the shoe, is combined with water to create an emulsion. This mixture of moisture and wax forms a very thin and perfectly smooth layer on the leather, giving it the desired shine.
The uniformity and homogeneity of this shine and its reflections attest to a successful mirror shine. The colours and all the shades of the leather frozen underneath come out in a way that is sometimes quite spectacular. On the other hand, the mirror shine is very fragile: the slightest scratch or even rubbing is sometimes enough to mark or attenuate it. Fortunately... only a little wax, water and elbow grease are needed to reproduce it.
This is how we are going to conclude this paper dedicated to leather, a material that we know well and that we love for its great capacity to go through time. Not everything could be discussed, the idea being to remain within general considerations, but if any questions arise, do not hesitate to comment on this article.