All You Need to Know About Cork Leather
Table of Contents
What is Cork Leather?
Cork leather is made from the bark of cork oaks. Cork oaks grow naturally in the Mediterranean region of Europe, which produces 80% of the world’s cork, but high-quality cork is now also being grown in China and India. Cork trees must be at least 25 years old before the bark can be harvested and even then, the harvest can only take place once every 9 years. When done by an expert, harvesting the cork from a cork oak does not harm the tree, on the contrary, the removal of sections of the bark stimulates regeneration which extends the life of a tree. A cork oak will produce cork for between two to five hundred years. The cork is hand cut from the tree in planks, dried for six months, boiled in water, flattened and pressed into sheets. A fabric backing is then pressed on the cork sheet, which is bonded by suberin, a naturally occurring adhesive present in the cork. The resulting product is flexible, soft and strong and is the most environmentally friendly ‘vegan leather’ on the market.
The Appearance, Texture and Qualities of Cork Leather
Cork leather has a smooth, shiny finish, an appearance which improves over time. It is water resistant, flame resistant and hypoallergenic. Fifty per cent of the volume of cork is air and consequently products made from cork leather are lighter than their leather counterparts. The honeycomb cell structure of cork makes it an excellent insulator: thermally, electrically and acoustically. The high friction coefficient of cork means that it is durable in situations where there is regular rubbing and abrasion, such as the treatment we give our purses and wallets. The elasticity of cork guarantees that a cork leather article will retain its shape and because it does not absorb dust it will remain clean. Like all materials, the quality of cork varies: there are seven official grades, and the best quality cork is smooth and without blemish.
Cork Leather vs Leather
It is important to recognise that there is no straight comparison to be made here. The quality of cork leather will depend on the quality of the cork used and that of the material with which it has been backed. Leather comes from many different animals and ranges in quality from composite leather, made from fragments of leather glued and pressed, and often confusingly labelled ‘genuine leather,’ to the finest quality full grain leather.
- Environmental and ethical arguments
For many people, the decision about whether to buy cork leather or leather, will be made on ethical and environmental grounds. So, let’s look at the case for cork leather. Cork has been used for at least 5,000 years and the cork forests of Portugal are protected by the world’s first environmental laws, which date back to 1209. The harvesting of cork does not harm the trees from which it is taken, in fact it is beneficial and prolongs their life. No toxic waste is produced in the processing of cork leather and there is no environmental damage associated with cork production. Cork forests absorb 14.7 tons of CO2 per hectare and provide a habitat for thousands of rare and endangered animal species. The World Wildlife Fund estimates that the cork forests of Portugal contain the highest level of plant diversity in the world. In the Alentejo region of Portugal 60 plant species were recorded in just one square metre of cork forest. The seven million acres of cork forest, situated around the Mediterranean, absorb 20 million tons of CO2 each year. Cork production provides a livelihood for over 100,000 people around the Mediterranean.
In recent years, the leather industry has come under sustained criticism from organisations like PETA because of its treatment of animals and the damage to the environment caused by leather production. Leather production necessitates the killing of animals, that is an inescapable fact, and for some that will mean that it is an unacceptable product. However, as long as we continue to use animals for dairy and meat production there will be animal hides to be disposed of. There are currently around 270 million dairy cattle in the world, if the hides of these animals were not used for leather they would need to be disposed of in another way, risking considerable environmental damage. Poor farmers in the third world rely on being able to sell their animal hides in order to replenish their dairy stock. The charge that some leather production is damaging to the environment is irrefutable. Chrome tanning which uses toxic chemicals is the fastest and cheapest way to produce leather, but the process seriously damages the environment and puts the health of the workers at risk. A much safer and more environmentally friendly process is vegetable tanning, a traditional method of tanning which uses tree bark. This is a much slower and more expensive method of tanning, but it does not put the workers at risk, and it is not damaging to the environment.
- Appearance and practicality
Cork leather is soft, flexible and light. Its elasticity means that it retains its shape and its honeycomb cell structure make it water resistant, flame resistant and hypoallergenic. It does not absorb dust and can be wiped clean with soap and water. Cork is resistant to abrasion and will not rot. Cork leather is surprisingly tough and durable. Is it as strong and durable as full grain leather? No, but then you may not need it to be.
The appeal of good quality full grain leather is that its appearance will improve with age and it will last a lifetime. Unlike cork leather, leather is permeable, it will absorb moisture, odour and dust and it will need to have its natural oils replaced from time to time.
The Origins and History of Cork and Cork Leather
Cork has been used for over 5,000 years as a way of sealing containers. An amphora, discovered at Ephesus and dating from the first century B.C.E. was so effectively sealed with a cork stopper that it still contained wine. The ancient Greeks used it to make sandals and the ancient Chinese and Babylonians used it in fishing tackle. Portugal passed laws to protect its cork forests as early as 1209 but it wasn’t until the 18th century that cork production began on a large commercial scale. The expansion of the wine industry from this point on sustained a demand for cork stoppers that persisted until the late 20th century. Australian wine producers, unhappy with the quantity of ‘corked’ wine they were experiencing and suspicious that they were being given inferior quality cork in a deliberate attempt to slow the influx of New World wine, started using synthetic corks and screw caps. By 2010 most wineries in New Zealand and Australia had switched to screw caps and because these caps are much cheaper to produce, many wineries in Europe and the Americas followed suit. The result was a dramatic drop in the demand for cork and the potential loss of thousands of hectares of cork forest. Fortunately, two things happened to alleviate the situation. One was a renewed demand for genuine wine corks by consumers and the other was the development of cork leather as the best vegan alternative to leather.
Is Cork Leather Eco-friendly?
Cork leather is made from the bark of cork oaks, using hand harvesting techniques which date back centuries. The bark can only be harvested once in every nine years, a process which is actually beneficial to the tree and which extends its lifespan. The processing of cork only requires water, no toxic chemicals and consequently no pollution. Cork forests absorb 14.7 tons of CO2 per hectare and provide habitat for thousands of species of rare and endangered species. The cork forests of Portugal host the greatest plant diversity found anywhere in the world. The cork industry is good for humans too, providing around a 100,000 healthy and financially rewarding jobs for people around the Mediterranean.
Is Cork Leather Biodegradable?
Cork Leather is an organic material and as long as it is backed with an organic material, such as cotton, it will biodegrade at the speed of other organic materials, such as wood. By contrast, vegan leathers which are fossil fuel based can take up to 500 years to biodegrade.
How is Cork Leather Made?
Cork leather is a processing variation of cork production. Cork is the bark of the cork oak and has been harvested for at least 5,000 years from the trees which grow naturally in the Mediterranean area of Europe and Northwest Africa. The bark from a cork tree can be harvested once every nine years, the bark is hand cut in large sheets, by expert ‘extractors’ using traditional cutting methods to ensure that the tree is unharmed. The cork is then air dried for six months, then steamed and boiled, which gives it its characteristic elasticity, and the cork blocks are then cut into thin sheets. A backing fabric, ideally cotton, is attached to the cork sheets. This process does not require the use of glue because cork contains suberin, which acts as a natural adhesive. The cork leather can be cut and sewn to create articles traditionally made from leather.
How is Cork Leather Dyed?
Despite its water-resistant qualities, cork leather can be dyed, prior to the application of its backing, by full immersion in dye. Ideally the producer will use a vegetable dye and organic backing in order to produce an entirely eco-friendly product.
How Durable is Cork Leather?
Fifty per cent of the volume of cork is air and one might reasonably expect that this would result in a fragile fabric, but cork leather is surprisingly strong and durable. Manufactures claim that their cork leather products will last a lifetime, though these products have not yet been on the market long enough to put this claim to the test. The durability of a cork leather product will depend on the nature of the product and the use to which it is put. Cork leather is elastic and resistant to abrasion, so a cork leather wallet is likely to be very durable. A cork leather backpack used to carry heavy objects, is unlikely to last as long as its leather equivalent.