Without doubt leather is ‘the’ sensory material: it has a rich, warm and distinctive odour, a naturally and individually grained surface pattern, and it even makes a sound (creaks) when being broken in. There are lots of variables to be considered when choosing leather for different applications. Things like breeding, age and care of the animal are all factors: for example, young calves are less likely to have damaged skin due to bites or scratches. This means that large, single pieces of leather are generally more difficult to find in high quality due to the difficulty in finding older calves with undamaged skin. Other considerations include the skill of the individual removing the hide, where on the cow the leather comes from, the method of preservation and the skill and method of the tanner.
Specifying leather also requires an understanding of grades, cuts and types of cowhide. Top grain leather, as the name suggests, is the outside layer and offers the best quality. The first-split layer is below the top layer and offers less quality; the second-split layer, generally considered waste, follows this. Kid leather is made from the skin of young goats and, as you would imagine, is very soft with a fine texture.
Willem de Ridder’s stools are made by fastening a leather sack around a mould and then boiling it. The leather tightens, and as it cools and hardens the mould is removed, leaving a construction that is strong enough to sit on.
Image: (Nothing to) Hide stool by Willem de Ridder
Key features
•Rich associations
•Its characteristics are enhanced with age
•Water repellent
•Can provide a good grip
Sources
Widely available.
Cost
The cost varies vastly depending on labour costs for production, type and quality of leather, and the size of the hide in relation to imperfections. There is also the issue of waste owing to the awkward shape of a cow, which means that using a hide will result in lots of small, unusable offcuts.
Sustainability issues
The environmental impact of leather is huge. There are hazardous chemicals used in the tanning process and there is also the impact of livestock and effluents from the production. The de-hairing process uses caustic lime and the tanning process can also involve hazardous chemicals such as chromium. In relation to livestock, CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) regulates the use of leather to ensure that species are not endangered as a result of the trade in leather from exotic animals.
Production
The production of leather involves three main stages: skinning and preparation, tanning and finishing, often referred to as crusting. Various surface finishes can be applied to enhance the finish and consistency of the leather. Corrected grain leather is a process whereby an artificial grain is applied to a hide to achieve a consistent texture, something very commonly done in the automotive industry. There has also been a trend in contemporary design for reverence for leather to be rejected in favour of a more brutal approach, which sees the material boiled and stretched to achieve compelling forms and rigidity. Hand-stitching and brogueing are combined with industrial patent finishes, to explore how traditional techniques can be freed from the staid world of bespoke leather goods.
Typical applications
It might be easier to start where there aren’t any typical applications. Leather is in everything from handbags to co-injection mouldings with plastics in luxury mobile phones.
| + | – |
|
–Tough and water repellent –Huge range of uses –Enormous variety of finishes |
–Can cause significant environmental impact |