The selection of leathers when manufacturing clothing

Leather has been used in clothing for thousands of years and remains popular today.

Manufacturers have a vast range of different leathers to choose from (see table 1). Approximately 10 to 12 per cent is used to manufacture clothing. China currently produces more leather garments than any other country. However, competition is increasing from India, Pakistan and other Asian countries, all of which have substantial herds of sheep and goats. Italy, Spain and Turkey are also large producers of high-quality garment leather for home and export consumption.

There are generally three different types of leather clothing: ‘classic’, ‘fashion’ and ‘protective’.

Classic

Many types of animal skins are used in the production of classic leather clothing. The black or brown nappa jacket was worn by military personnel during World War II. In the 1950s, these jackets were worn by film stars and, as a result, ‘flying jackets’ became a popular item during the 1960s. Originally made from soft unsplit full grain sheepskin, nappa leather is now also made from goatskin or grain split cowhide. Chromium tanned dyed-through leather is normally preferred because it can produce the softness and colour fastness required and, if necessary, be adapted to give some water resistance.

Table 1: Summary of leather used for clothing manufacture
Origin of leather	Type of leather
Sheep and lamb	Nappa
	Suede
	Double-face
	Chamois
	Skiver­
Cow	Nappa
	Nubuck
	Split
Goat and kid	Full grain and suede
Pig	Full grain and suede
Exotic and fur-bearing animals	For example, snake and mink
Kangaroo	Nappa mainly

Nappa leather is usually lightly finished with thin films of pigment bound in resins, such as polyurethane or acrylics. The better quality and more expensive nappa leathers are dyed and finished as ‘aniline’, with fewer grain defects and no finish coating. Sometimes a clear coating is applied, perhaps with dye, but without pigment. Nappa cowhide is produced internationally in smaller quantities than sheep and goat, but it has the advantage of having a larger skin area – around 40 square feet compared with an average of five to eight square feet from goat and sheep.

Suede leather for jackets in black, tan or brown is also popular. Leathers with the best properties for clothing tend to be made from sheep, lamb, goat or kidskins. These produce very soft leathers with a pleasing handle and are finished by abrasive action on the flesh side of the full skin to create a velvet-like suede appearance. Cowhide suede splits are produced from the flesh split and usually abraded on the original grain side of the split. These are often regarded as the cheaper end of the suede market. Suede leathers may be manufactured with a degree of resistance to rain by using chemicals such as silicones or fluorocarbons during tanning. Some fluorocarbons, such as per and polyfluoroalkyl substances (PFAS), are subject to legal restrictions in many parts of the world. Such restrictions are increasing, so information about the exact fluorocarbon treatment is essential in order to ensure compliance.

Double-face sheepskins and lambskins are called by these names because they are produced with the original wool attached and the flesh side is abraded (sueded). These skins are primarily used to make luxury garments that provide thermal insulation in cold climates.

Pigskins are produced in both nappa and suede finishes, but have less scope because of the highly visible and characteristic hair follicle holes remaining after the bristles have been removed. Skivers, which are the grain split of the sheepskin (without wool), can be used to make nappa-type finished clothing leathers. However, the tear strength is low, and seams require reinforcement. Skivers are more successfully used in the production of hats.

Suede or nubuck leather impregnated with fats and oils is also available. However, it should be noted that the movement of these impregnants during wear can cause discolouration and present difficulties during cleaning – especially dry cleaning.

Chamois leather, named after the Chamois, a goat-like antelope native to the European Alps, is made by oil tanning the flesh split of a sheepskin. The resulting leather is very soft and has been used for making garments such as dresses, underwear and bikinis. Chamois leather is highly absorbent to water and dirt, which is why its major use is in cleaning windows and automobiles. When used for clothing, chamois leather requires care to be taken both during wear and subsequent cleaning.

Fashion

Today, leather is highly fashionable and many famous designers put leather garments in their collections. Colours, effects and styles vary from season to season. Furs, or the combination of leather and furs, are also used. In addition, nappa and suede (mostly sheep and goat) are seen in fashion clothing as they can be produced with a very soft, smooth handle, which makes them ideal for producing effects such as folding and ruching.

The bright colours produced by the fashion industry challenge the tanner to make leathers that are both colourfast and fade-resistant. Designers also like to combine different skins and other materials in the same garment, which can present problems for the cleaning industry.

Protective

Leather, mainly full grain nappa, is popular with motorcyclists for both the resistance to abrasion it offers and its style. The thicker leathers tend to offer more protection. Most clothing is made with leather around 1 to 1.5 mm thick, but 2 mm thick leathers can give excellent protection in accidents, often combined with tough materials such as Kevlar. However, the thicker the leather, the more likely it is to be uncomfortable and restrict movement.

Reinforcement is often built into motorcycle clothing to give extra protection to elbows and knees. Kangaroo leather is used for motorcycle garments in limited quantities, and its advantage is that it has a higher tear strength for lower thicknesses, compared to cow and sheep leather.

Leather garments, made mainly from cowhide or splits, are used to provide protection in industrial situations in the form of leg guards, sleeves, jackets or aprons. Fire, heat and water resistance may be built into the leather to give the protection needed.

Cutting leather

In cutting and matching the panels of leather during garment manufacture, it is essential that the main panels are from the firmer, better quality areas in the centre of the skins to avoid structural variations which can give rise to looseness, especially in the flanks of sheep leather.

Lapels, collars and pocket fronts should also be cut from firmer leather. Leather from different batches should not be used in the same garment to avoid colour change problems in wear, especially after cleaning. When mixing other materials with leather, care must also be taken to avoid colour transfer from one material to another.

Caring for leather garments

During the transport and storage of leather garments, prior to sale, temperature and humidity must be controlled to avoid staining and damage from mould and bacteria. Strong lighting and pollutants may also cause discolouration of the leather. Pressure marks and creases, due to packing clothing items too closely together, may be difficult to remove later. It is important for the garment producer to supply proper aftercare information to the final customer.

Finished grain leathers may be wiped clean with a damp cloth. Worn or scuffed areas can be restored with specific leather products, often found at shoe repairers. Brushing suede after wear with a dry sponge or soft cloth while the leather is slightly damp will restore the nap. Light soiling may be removed with specialist cleaning products, a rubber block or pumice stone. All garments should be dried naturally, away from direct heat and stored on a well-shaped hanger.

Cleaning

Cleaning leather clothing is complex and often requires specialist attention. An initial inspection and discussion between the cleaner and the customer are essential. Potential problems after cleaning include shrinkage and changes in colour and appearance due to previously undetected faults in the leather. Natural defects, such as scars, vein marks and wrinkles, may become more apparent after cleaning and correctly selecting the appropriate cleaning solution is vital. Oils lost during cleaning may need to be replaced. Adhesives used in manufacturing the item may dissolve or soften and may also need replacing after cleaning.

Testing

Laboratory testing of any leather prior to production is essential. The main physical tests are tear strength and flex crack resistance of the finish (in normal and cold conditions).

Depending on the finish, the colourfastness tests required are resistance to rubbing, light, water, perspiration and water spotting. Innocuousness tests, including for chromium VI, per- and polyfluoroalkyl substances (PFAS), and banned aromatic amines from some azo dyes should also be carried out. In addition to these assessments, SATRA can carry out permeability and breathability tests on materials or articles to help develop comfortable leather garments and advise about other appropriate chemical and physical tests.

In the case of protective clothing for PPE or motorcycle applications, there are mandatory legal requirements in place for specific testing. SATRA can also help to meet these requirements.

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