What is the technology behind leather tanning? The leather making process is one of the oldest technology and started to be developed with the meat consume. There are different methods of preparing animal hides and skins for future utilization as leather. Tanning is the process of treating animal skins to produce leather – a durable and flexible material. Untreated skin would harden out and putrefy as it is an organic material, making its utilization in the articles we wear not possible. The aim of the tanning process therefore is to prevent this from happening through modification of the protein called collagen. Tanning can be performed using either vegetable method with plant polyphenols, mineral methods with metal salts (in particular chromium) and metal-free method with synthetic tanning agents, aldehyde tannages and oligomers. (source: “Modern tanning chemistry” from Anthony D. Covington) The choice, which method will be applied, affects the final properties of the leather, human health and environment. The continuous shifting of leather industry and its growth to the east and south is justified with lower labor costs and less stringent environmental legislation. It is not just the matter of lax environmental law, rather its enforcement is the issue here. There is still long way to go, to make people understand, which price is paying nature and workers of this industrial sector in 3rd countries. Chrome tanning The prevailing methods of leather tanning in the fashion industry are based on chrome-tanning. Indeed the products produced with vegetable tanned leather have very small market share. Chrome tanning (also known as mineral tanning) is the most popular from mineral-based methods. The tanning agent used in process is chromium sulfate. Chrome tanning was invented in 1858, which makes it one of the youngest methods and the most popular one by the industrial manufacturers. Chrome tanning is an effective method to produce a soft uniform leather in very fast way. The whole process take about a day and this facts made this manufacturing method so popular and widespread in the leather industry. Sounds good, doesn’t it? That’s a reason why about three quarters of all leather used in fashion industry is chrome tanned leather. But the advantages of chrome tanning have their price. First of all, chrome tanning process is harmful for environment and dangerous for people working at tanneries or live nearby. As any heavy metal chrome is extremely toxic and have carcinogenic properties. As this method is easy and doesn’t demand extraordinary skills, many tanneries are situated in the 3rd world countries in order to keep down the manufacturing costs. In many cases the working environment in this countries doesn’t provide protection to the workers and they have direct contact to such strong chemicals, having as consequence many diseases and short live expectation. There are no strong restrictions on the production, so all chemicals used in the tanning process just flow without being filtered into rivers. The damage to the nature is not measurable and the effect on the human health is terrifying, when the birth rate of the healthy children in this area and live expectation is very low. But developed countries are also affected by this destructive and careless approach not just directly through the utilization of such leather, but also through contaminated supply in the food chain. The leather waste from many manufacturing locations in the 3rd world countries is converted into flower, which is fed to shrimp farms. This shrimps are contaminated with all this heavy minerals and are exported everywhere in the world landing in our dishes. Despite being publicly recognized for these significant downsides, it is still the most used method in the fashion industry. Vegetable-tanning Vegetable-tanning is one of the oldest methods of making leather – this has been used for thousands of years. This method is completely chromium-free, so it doesn’t include any harmful chemicals. It is an old-world, artisanal process that takes advantage from the tannic acids naturally found in some plant species, by using the barks, branches, leaves and even some fruits in some specific techniques. This specific techniques require experienced and skilled workers and each tannery keeps its recipe and process secret. The skins keep its light rose-beige appearance before being painted and has its typical woody and earthy smell. There are some disadvantages of vegetable-tanned leather, which need to be mentioned to be fare: Many steps in production process are still leaving its footprint on the environment, especially the ones performed before tanning Tanning requires high consumption of water, although the result is harmless opposed to the chrome and aldehyde methods Depending from the plant phenols used for the process the production time is long and vary between 3 weeks up to 2 month Long production times are causing high final cost But there are also awarding advantages unsurpassed by any other tanning methods: It doesn’t negatively affect a human health, especially important by the direct contact with the skin Such properties as high durability and strength provide this material a long life cycle Due to its bio-degradable properties it has low impact on the environment It has remarkable esthetics, with more vivid color appearance, more natural and organic look Its aging qualities, influenced by exposure to natural elements, nurture unique patina acquired after some time Almost completely forgotten valuable knowledge of old craftsmanship were recently retrieved to provide an alternative material choice for conscious consumer. This revival revitalized the local society and the deeply rooted tradition could survive in the era of consumerism. So why choose vegetable-tanned leather goods? Because you will be doing a responsible choice and purchase a sustainable product, which will last, give you comfort and allow you to diminish your footprint on the environment.