raw material
So soft, so delicate, so light – the raw material from which the cashmere yarn is made is the cuddly downy hair of the cashmere goat, which grows under the longer, covering contour hair and is only formed under extreme weather conditions.

The longer and finer the fiber of the raw material, the thinner and more valuable the cashmere thread spun from it. Cashmere fiber is a natural fiber of animal origin. Animal fibers are primarily divided into wool (sheep), fine hair (llama, alpaca, mohair, angora, cashmere, camel), coarse hair (cow, goat, horse) and silk.

In order to adapt to environmental conditions, all species with hair follicles - including humans - have developed fibers over the course of millions of years that protect them from the weather. This can be hair or fur - a natural, vital adaptation that regulates temperatures, absorbs sunlight or has tactile functions.

A four-season fiber
In general, the primary hair of the goat is one of the oldest natural spinning materials in the world and is known as hair yarn. The secondary down of the cashmere goat is considered to be one of the finest hair yarns of all. The cashmere fiber is an extremely complicated protein fiber with special properties: extremely light, flexible and pliable due to its special surface, expandable in volume and elastic like rubber. The tear strength is 2.5 grams.

Like sheep's wool, cashmere fiber is able to absorb moisture in the form of water vapor and can absorb up to 30 percent of its own weight.

Cashmere is breathable, insulates well against heat and cold and is extremely warm. It is therefore also referred to as a "four-season fiber". Cashmere is antistatic and absorbs very little dust from the air. Its natural protective layer makes it largely resistant to stains. The fiber is non-flammable, 100 percent biodegradable and able to adapt optimally to the environment - all properties that make cashmere so unique and predestine it for textile use.

Structure and design
The morphological structure of the cashmere fiber is similar to that of fine wool. The fibers can be imagined as long, hollow horn threads made of α-keratin, which essentially consist of highly cross-linked polypeptide chains. The color of the fiber is determined by the pigment melanin, as is the case with human hair. Roughly speaking, the fiber is made up of three layers: the outer cuticle made of keratinized, flat and overlapping cells, which are oriented towards the tip of the hair like a pine cone.

This layer surrounds the fiber stem (cortex), which consists of polymer spindle cells and forms the main part of the hair (approximately 80 percent). Inside is the medulla, which is usually hollow and filled with air.

In contrast to the coarse scale layer of a sheep's wool fiber, which has a high, roof-tile-like appearance, the cuticle of the cashmere fiber is hardly scaled, its ladder-like scale cells lie smooth and even. Viewed under a microscope, cashmere hair is reminiscent of slightly bent bamboo tubes. The low scale height of the downy hair fiber is the reason for the soft appearance and the pleasant feel of the raw material. The coarse guard hair of the cashmere goat, on the other hand, has similar external characteristics to wool, i.e. it is scalier and stronger.

The quality
Four essential parameters determine the quality of the cashmere fiber: length, cross-section, color and proportion of remaining guard hairs in the raw material. The individual hair can be up to 75 millimeters long. The length of a very high-quality fiber is usually between 38 and 42 millimeters. The fineness or cross-sectional size is given in microns or millimeters (a micron is a thousandth of a millimeter, 1 μm = 0.001 mm). The finer the hair, the higher the quality. The diameter of particularly fine hairs varies between 14 and 18 microns, which corresponds to approximately one sixth of the diameter of a human hair. 5 Fine merino wool is around 19 microns, normal new wool is 22 microns.

The color is also a quality-determining feature. Natural white cashmere is the most valuable. It is so sought after because it is the easiest to process and dye - it is like a precious item of particularly high value. In China, where cashmere is often referred to as "soft gold" or "white gold", there are more cashmere goats with white hair than anywhere else. The supply share of pure white cashmere raw material here is 60 percent, whereas Iran, for example, supplies "only" 20 percent white raw material. The rest is either light brown, gray or dark brown. Overall, however, the population of white cashmere goats is small. Piebald goats with hair of different colors such as brown, light gray or black are in the majority. They developed over the centuries through the natural genetic cross-breeding process. Nevertheless, the lighter the fibers, the more expensive the raw material. If white duvet hair is mixed with hair of a different color when combing or if it is packaged without taking the colors into account, its value drops because it is very time-consuming to sort the raw material according to color afterwards. The practice of bleaching dark raw fleece using the white bleach process does occur, but always means a loss of quality. Similar to human hair that is bleached or dyed, cashmere is extremely sensitive. The elasticity disappears, the softness is lost, the feel becomes noticeably harder, and it appears brittle and stressed. Chemical treatments should therefore be avoided as much as possible.

The classification
Another decisive factor in the evaluation of cashmere is the proportion of guard hairs in the cleaned raw material. The longer primary hairs cannot be completely removed either during the production of the duvet or during the manufacturing process. Depending on the use, a residual proportion of 0.1 to 0.5 percent is the rule. Particularly valuable yarn should not contain more than 0.1 percent guard hairs. A yarn of the highest quality is called cashmere two ply28, it is ideally white, extremely fine (14 μm–17 μm), at least 32 millimeters long and is twisted from two cashmere threads. It is therefore stronger and more elastic than the so-called single-ply yarn. 1 kilogram of cashmere two ply28 produces a yarn that is 28 kilometers long.

In order to check the impeccable quality of their goods, reputable cashmere dealers and producers use guidelines that correspond to internationally established standards. Accordingly, one speaks of genuine, pure cashmere if the fiber cross-section does not exceed the maximum upper limit of 19 microns. A coefficient of variation of 24 percent is permitted, and a tolerance value of three percent for hairs with a maximum diameter of 30 microns is also permitted.

100 percent cashmere
The market value of cashmere depends on the quality checked. The prices for raw materials vary and are in a range of around 60 to 150 euros per kilogram. Pure white, 32 millimeter long cashmere hair from China currently costs around 125 US dollars, making it one of the most expensive animal hairs in the world.

Because merino wool is up to ten times cheaper in comparison, the textile industry has a great interest in clearly identifying and declaring textiles made from relevant animal hair - and in recognizing incorrectly labeled raw materials and goods. According to the European Textile Labeling Regulation, the label "100%", "Pure" or "Whole" may only be given to textiles that consist exclusively of one fiber. The manufacturing tolerance mark here is three percent by weight of foreign fibers, provided that this proportion is justified by the fact that it is technically unavoidable with good manufacturing practice and is not the result of systematic addition.

"100% cashmere" - a product declared in this way is therefore of the highest quality and made from pure cashmere hair. If a product label is to say "cashmere", it must be guaranteed to contain at least 85 percent cashmere. A sweater with cashmere content must have a minimum cashmere fiber content of 14.5 percent. Despite these regulations, cashmere is still often incorrectly declared. The price difference between cashmere and other animal fibers (alpaca, angora, mohair, yak hair, camel hair) is enormous and leads to animal hair blends being put into circulation and labeled as pure cashmere. The German Wool Institute (DWI) estimates that at least 25 percent of cashmere goods worldwide are incorrectly declared - a figure that unsettles consumers and puts the industry in a negative light, especially since there are no applicable quality seals or institutions that perform control functions.

Alpaca fibers treated with chlorine, sheep's wool coated with silicone particles, camel hair trimmed with chemical softeners - deceptions of this kind are used to make hair or wool smoother, thinner and softer so that it feels like cashmere. Tricks that often go unnoticed, because laypeople and even experts often cannot tell what materials are involved. Imitations cannot be distinguished from cashmere with the naked eye.

Retail chains
Retail chains and designer labels use the opportunity of scientific fiber testing. This is offered by a number of international laboratories that are accredited worldwide by the International Wool Textile Organisation (IWTO) and the Cashmere and Camel Hair Manufactures Institute (CCMI). They have the expertise and experience to subject fibres to certain measurements. Essentially, four internationally standardised provenance procedures are used to identify and test and determine the actual fibre content of a product:

Light microscopy (LM), scanning electron microscope (SEM), protein and DNA analysis. Light microscopy is an optical method - historically relevant - that has been used since the 1950s. It makes the internal structures and pigmentation of the fiber visible and is based on the recognition of the scale layer of the fiber magnified a thousand times. In the scanning electron microscope method, so-called "topographic fingerprints" on the surface provide information about the optical properties of the fiber. The most common method today has been scientifically researched and modified since the early 1980s. The finest fiber snippets are moved under the microscope following a grid system. Parameters such as the scale pattern and number of scales per micrometer of fiber length, fiber diameter and structure of the fiber surface are recorded and recognized.

The most important criterion in which cashmere fibers differ from sheep fibers is the height of the scale edges. The scanning electron microscope method is able to calculate and evaluate these measurements. Protein analysis is a physical-chemical method that is based on the fact that different proteins occur in different species in different frequencies. It separates and filters proteins and thus provides information about the genetic origin of animal hair. As a carrier of genetic information, DNA is suitable for the unambiguous identification of a species. It occurs in hair in sufficient quantity and quality. The analysis compares the DNA cashmere sample to be identified with relevant comparison samples and checks for possible matches.