The hand of textiles – definitions,achievements,perspectives – a review

Introduction

The hand of textiles has been a subject of hundreds of analyses since the 1930s, when Peirce ¹ made an attempt at an objective estimation of hand related features. It was believed that some of the general features of textiles like softness or stiffness could be related to the mechanical analysis of those textiles; for example, stiffness could be measured during flexural rigidity tests. The results of those mechanical test analyses were to be the objective equivalent of the subjective judgement of stiffness. Although this and other similar studies^2–4 have been performed, until the present moment, hand has not had a uniform and concise definition mainly because of its subjective nature and due to obstacles to finding the relation between feelings related to textiles when they are handled.

Definitions of hand

The hand of textiles is a crucial element influencing the purchase of textiles by individuals. Knowing the hand features of produced textiles and being able to analyse or predict them on the basis of textile components could provide producers and hand analysis experts with a tool which would allow individuals to be assured of final products with the best hand features, which may refer also to the judgement of ergonomic or sensorial and thermal wear comfort.^5,6

The hand (or handle) has been defined in many ways so far. Depending on the author of the definition of the hand of textiles and the orientation of his or her studies, it is defined as:

a subjective assessment of a textile obtained from the sense of touch; ⁷

These definitions clearly present lack of congruency, as mentioned above. This is also the reason why this area still arouses great interest.

On the basis of our own experience and studies we propose our own definition of the subjective hand of textiles:

‘The hand of textiles based on the holding of the textile or the smoothing of the textile with the palm is an act of experiencing the textile’s thickness and surface, and other textile physical features against the skin of the palm which evokes the impressions related to physical features of the material perceived by the fingers and palm skin receptors and transferred neurologically to the cerebral cortex. The judgement is given after referring to the personal experience of the person who makes this judgement as well as his or her natural skin sensibility.’

The subjective hand analysis techniques are related to analysis of the opinion of users of textiles by the application of different interview and questionnaire methodologies used after an appropriate presentation of textiles. The subjective analyses are usually direct methods of making hand measurements, which means that they categorize the fabrics immediately by describing them using adjectives, for example soft–hard, limp–stiff, cold–warm, smooth–rough, and so on.

Due to the large number of data involved, a statistical analysis and artificial neural networks are applied to draw conclusions ¹⁵ and to create a learning machine ¹⁶ to learn how to perceive the textiles, thus allowing prediction of the subjective hand. ¹⁷

The other pole represents the objective hand analysis techniques, which are related to analysis of chosen mechanical properties of textiles to form components of a final ‘value’ or ‘feature’ called the hand of textiles. Though these kinds of techniques were not developed first, it seems to be logical to present them as a primary technique before subjective techniques due to their technical antecedence to subjective techniques and to give a better understanding and flow while reading the paper.

Usually, objective methods do not characterize the hand directly; they provide certain mechanical parameters that are believed to present components of hand, like fabric stiffness and compressibility. However, there are also objective and direct methods at the same time. As a result of the measurements they indicate only some aspects of hand of the fabric. Examples are the ring method and the slot method. They give information concerning drapability and frictional features of textile materials. ¹⁸

Hand of textiles versus their mechanical properties

One of the oldest and most influential studies, by Peirce, ¹ established a base for many scientific works carried out in the field of the hand of textiles. It lays the foundations for the analysis of bending length, flexural rigidity, and bending modulus. It also explains the influence of air humidity while taking the measurements and time of taking the measurements on the results.

It is necessary to perform physical tests that analyse and reflect the sensations felt and to assign numerical values to the measurements. We already know today that what is mentioned here is just a base. The hand of textiles is far more than that.

Studies are being developed in which trials are based on the relation between the yarns in the material and the fabric hand, like the paper describing fabric stiffness on the basis of hanging – the heart test; compliance on the basis of the shape of a force–elongation curve; liveliness on the basis of a recorder trace test; leanness and bulk of textiles on the basis of coverage definition; compressibility and thickness on the basis of the concept of springs; and contact warmth, drape, smoothness, and lustre as well as covering power and contour retention and resilience.^18,19

However the most meaningful studies related to the hand of textiles were performed by Sueo Kawabata and Masako Niwa. They established the Hand Evaluation and Standardization Committee (HESC) to finally create the so-called Kawabata System (KES). Japan’s Textile Machinery Society has published standards incorporating samples of appropriate fabrics for the overall fabric hand called the Total Hand Value (THV) focusing on men’s winter suiting’s. ¹⁸ The Committee elaborated similar types of standards for fabric hand attributes or Primary Hand Value (PHV) considered important in the fabric hand evaluation of both men’s winter and summer suiting fabrics and ladies’ thin dress materials. The PHV attributes chosen by the HESC are koshi (stiffness), numeri (smoothness), and fukurami (fullness and softness). The PHVs for men’s summer suitings are koshi, shari (crispness), hari (spread, anti-drape), and fukurami.^14,18 The instrument called KES manufactured by Kato Tech. Co. of Kyoto measures physical, mechanical, and surface properties of fabrics using four separate instruments.

The KES system has been successfully applied in the analysis of many kinds of textiles including hygienic textiles like nonwovens^20,21 and blankets. ²² Knitted structures can be estimated by means of the KES system. ²³ There is also a large group of publications that verify the hand of textiles by means of the KES system by comparing different textiles with each other and applying some modifications to the measuring technique or comparing different methodologies.

It has been proved that the weave and yarn density, raw materials, ²⁴ and finishing ²⁵ influence the hand of textiles. Finishing has a considerable effect on the bending properties of all woven fabrics and knitted synthetic fabrics, although the effect is less for knitted wool fabrics; the frictional resistance to deformation (in both bending and shear) is always much more critically affected by finishing than the elastic rigidity of the fabric. Fabric bending properties depend on fabric thickness and other constructional variables, but shear properties show much less systematic variation with such parameters and are largely determined by the type of fabric construction itself.^18,26

To overcome certain limitations of that set of modules a new set of devices called the Fabric Assurance by Simple Testing (SiroFAST) system has been developed by the Division of Wool and Technology at the Australian Commonwealth Scientific and Industrial Research Organization to meet industry needs for a simple fabric performance tester.

The SiroFAST system for objective measurements of fabric mechanical properties has been developed to measure the properties of fabric that are important in the manufacture of garments. It has not been oriented towards hand measurements; however it turned out that it may provide outputs similar to KES from the measurements of fabric samples so the results of the tests performed on the fabric samples may be used to estimate the hand of fabric. It is believed that this system is less complex to use. It consists of three instruments and a test for dimensional stability.

Although the measurements are relatively simple in comparison to Kawabata measurements, the interpretation of the results is still complex.^18,26

However there are some alternatives to KES, SiroFAST, and Fabric Automated Modular and Optimisation Universal System (FAMOUS)^27,28 like Instron, which estimates the mechanical properties of the materials. The idea of involvement and adaptation of the Instron device to measure ‘hand features’ of fabric came from the relative lack of accessibility of all modules of the KES system in the past, and most of all due to the need for an alternative to the time-consuming test by KES. Details of the performance of the test to estimate the mechanical parameters of textiles related to the hand of these textiles with using an Instron were describe by the studies of Pan et al. ²⁹ and others.^30–32

The difficulties of tests performed with Instron in comparison with KES are related to keeping an appropriate level of stress of the sample, which should be lower than the stress at rupture; however the stress level should allow non-linear characteristics of the tested sample to be detected. The second difficulty and inconvenience is related to the shear test. The tensile test has been modified so that the shear test can be performed with Instron. The shear test has been replaced by the tensile test and the test for the tension of the sample at 45° to the warp and weft direction is performed with Instron. Although some divergences have been reported between the shear test and the diagonal tensile test, both tests supply very similar information when low stress analysis is performed. ³²

Other studies present the development of unilateral devices for measuring only some features of the hand of textiles, for example the ‘Fabricometer’, ‘Handleometer’, and fabric stiffness meter.^33–35 One technique for fabric handle is based on the use of a simple device fitted to a tensile testing machine, and measures the force generated while passing a fabric specimen through a ring. The method proved capable of detecting differences in fabric handle between comparable fabrics. The force needed to withdraw the fabric through the ring increases as more of the specimen is introduced into the ring. The maximum value of the force occurs when the entire specimen has nearly passed through the ring. The fabric specimen gets folded, sheared, bent, compressed, and rubbed against the interior wall of the ring during withdrawal. ³⁵

The El Mogahzy–Kilinc hand measuring method is worth mentioning as a modification of the unilateral direct subjective method of estimation of the hand of textiles ¹⁸ The idea of using a funnel medium instead of a ring or slot arrangement is to provide better simulation of fabric hand. The contoured flexible surface of the light funnel simulates anticipated hand modes such as drapability, stretch, and surface friction.

Pan ³⁶ has built a commercially available instrument based on the extraction method, which pushes a fabric through a ring. The testing methodology has been fully computerized and the extraction curve (displacement vs. extraction force) provides more data to compare to previous attempts.

The FAMOUS system^27,28 offers the possibility of performing measurement under a complex load similar to real usage of the material. The bending rigidity test has been modified to compare to KES and is performed in the form of a buckling test. The sample is subject to buckle in the horizontal plane. The system uses the same rules for the tensile, shearing and compression tests as the KES in the form of a single device, contrary to KES and FAST.

Perception of textiles – a physiological approach

For a better understanding of the complexity of subjective hand assessment a physiological background is presented. Haptic sensing analysis (tactile sensing) comes before subjective hand assessment, as that methodology is based on personal appreciation of the object by the sense of touch.

The tactile sense does not possess any localized sensory organ in contrast to the visual and auditory senses. ³⁷ In fact, the sense of touch operates all over the skin like a distributed phenomenon. Additionally, in terms of the area covered by the senses, the transduction of tactile signals is distributed over a considerably wider surface than a single localized sensory organ such as eyes or ears. The nature of tactile sensing through the skin is not simply the transduction of one physical property into an electrical signal. This is mainly because the sense of touch assumes many forms.^37,38 These forms include the detection of temperature, texture, shape, force, friction, pain, itching, and other related forms – physical properties. The relation between these different aspects of the tactile features is not clearly understood. To touch is to use one’s skin to have physical contact with another object.

The following description presents only selected aspects of skin physiology. They allow a better understanding of the perception of textiles through the skin.

Tactile receptors are located in clusters in human skin and look like jelly material. When they are stimulated or squeezed in some way, the layers rub against each other, causing an electrical nerve impulse to be generated.

The skin of the hand, in particular, is highly specialized to provide detailed tactile feedback.^37–41 The information about the external and internal environment activates the central neural system of the human by means of different receptors. These receptors are transformers, in fact: they transform different forms of energy in the surroundings of the organism into functional potentials in neurons.

Nerve and muscle cells and receptors belong to a class of excitable cells. In response to different stimuli (chemical, electrical, mechanical) a perturbation of a membrane cell potential may take place, which leads to the induction of functional potentials (the unit is mV).

Organs of the skin sense

There are four types of skin senses:

touch/grip (grip is a sustained touch);

The appropriate receptors for these skin senses are not equally distributed.

Detection of roughness and texture

Roughness, like other aspects of hand, has no unified definition. However, in relation to the perception of roughness by the human finger, it can be defined as undulations or protrusions of a surface that are of a much smaller scale than the fingertip but large enough to permit tactual discrimination between the surface in question and the one that is smooth.^37–41 Roughness perception is made by the lateral movement of the finger over a surface. When the finger is moving over the surface, the Pacinian corpuscle units all over the finger will fire, providing information about the stimulation of the finger. It has been suggested that roughness is related to vibration sensing, with the Pacinian corpuscles presumed to code high frequency vibration and the FAs to code low frequency vibrations. It has been proposed that because the roughness measurements require both normal and shear forces, the SA units could not be excluded in roughness measurement. The Pacinian corpuscles are also sensitive to vibration and may code roughness. In addition to roughness, both compliance and viscoelasticity contribute to surface texture. The human hand perceives those properties through the vibrations set up in the skin as the hand moves across the object.^37–41 Table 1 presents a concise summary of the relationships between attributes of fabric hand and the appropriate receptor or receptors.

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Table 1.

The characteristics of skin mechanoreceptors skilled to react on fabric features composing certain attributes of fabric hand.^37–41

Name of the mechanoreceptor	Pacinian corpuscle	Ruffini endings	Merkel’s disc	Meissner’s corpuscle	Free nerve endings
Number of receptors (cm2)	21	49	70	140	connected to many
Sensed parameters	touch, roughness, vibrations	pressure on skin and skin stretch	pressure of the skin and texture	vibration, touch	responds to mechanical, thermal, or noxious stimulation
Attributes of fabric hand	softness/ hardness/ roughness	compressibility/ elasticity/ harshness/ slippery	roughness/ hairiness/	slippery	cold/ warmth/ elasticity

Hand of textiles versus subjective techniques for its estimation

The hand of textiles is by definition subjective. So it is related to individual perception and sensitivity of the skin receptors of the human hand.

The analysis of subjective assessment of the hand of textiles was performed parallel to and independently from the objective techniques. Various physical characteristics of a fabric combine to produce the phenomenon of hand, from one side, and differences in assessments of hand originate from differences in human background and abilities to detect this complex behaviour, from the other side. ³³

There are many different approaches related to the analysis of hand in a subjective manner. Usually a group of experts is asked to estimate the hand of textiles by, for example, holding them. However there are tests that engage both expert and ordinary users of textiles ³³ that can use different registers to describe their perceptions. ⁴² Sometimes an interview with an unskilled user is applied. ⁴³ In such cases a bipolar system of description of the tested fabric is often used.

The unskilled user of textiles is asked to judge whether the textiles presented to him or her are stiff or pliable, soft or hard, elastic or inelastic, springy or limp, compact (dense) or open (loose), rough or smooth, harsh or slippery, and warm or cool. However, unskilled users are also asked to rank features like smoothness, softness, firmness, coarseness, thickness, warmth, harshness, stiffness, liveliness, and so on, by giving them values from 0 (no attribute) to 5 (a very strong attribute) ⁴³ or by ranking a total hand from excellent to poor. ¹⁵ Separate issues are related to the manner and the order of the presentation of samples and the scenario of the test, such as how many samples should be estimated by users at once (fatigue has a possible negative influence), ⁴³ as well as the colour, structure, surface, and external conditions (light). It seems logical that the colours of the estimated samples should be the same or at least similar when presented to unskilled users to avoid the influence of the personal preference of the judges. Another issue is the development of vocabulary that refers to hand estimation and psychological influences on judgements; ⁴⁴ experts and non-experts tend to use different descriptors. ⁴⁵ Some other studies have developed a touch–vision relation to verify whether two senses can mediate similar ratings of texture attributes.^46–49 ‘Blind tests’ are performed to prevent the person’s haptic perception from being influenced by visual perception, so the person can only touch the samples without viewing them. ⁴⁵

It seems that the uniformity of the group of persons who estimate the hand subjectively is important. Nationality, age (the sense of touch, suffers from deleterious effect of age – the effects of ageing are substantially greater in the Pacinian corpuscles than in other mechanoreceptors), gender, touching time, applied force, the speed of finger movement, ⁵⁰ menstrual cycle (cutaneous sensitivity to painful stimuli, to changes in skin temperature, and to tactile stimulation have also been found to vary with the menstrual cycle; after the onset of menstruation, thresholds of Pacinian corpuscles increase reaching maximum near the ovulation time) and occupational activity,^51–55 with educational background as a secondary issue along with everyday life, all have an influence on the fingertips’ skin surface quality.

As reported previously, ⁵⁶ individual observers differ considerably in their ability to rank fabrics with respect to stiffness and liveliness, and if the fabrics differ only slightly, the opinion of one observer may be of little value, especially if he or she is unskilled. It was also found that the mean stiffness and liveliness scores of a group of observers could be closely correlated with the results of the cloth-bending hysteresis test, which is therefore more valuable than the assessment of one or two individuals.

A technique based on the semantic differential method of consumers’ approach to hand knitting yarns has been developed to establish an appropriate register for use in studies. The divergences between prediction of the hand of the fabric and general perception on the basis of the hand of the yarn itself as a component of that fabric were analysed. It seems that responses to yarns in the ball state and the fabric state differ markedly in some instances, indicating that at the point of purchase, initial impressions may prejudice purchasing decisions. ⁵⁷

To provide information related to specific expressions, evaluators were given written definitions of five quality words or attributes that might influence the hand preference, which are quoted as an example and another proof of the importance of using a register that is uniform. According to the authors: ⁵⁸

Stiffness is the resistance to bending: if the fabric bends easily, it is flexible and not stiff.

Correlations established between primary hand expressions and mechanical properties show that subjective qualities such as bendability and stretchability can be reliably indicated by simple laboratory tests; however, measurements of the friction coefficients fail to correlate with the sensory perception of surface smoothness.

Combination of objective and subjective systems

There are many works that combine both objective and subjective systems for measuring hand,^3,59 as it is believed that objective systems do not ensure a full representation of hand due to their lack of a human element. Conversely, subjective methods are believed to be dependent on temporary human moods, which can be easily observed in tests with consumers, rather than trained experts, and produce results with a relatively high coefficient of variation concerning the judgement of specific features.

The objective methods provide quantified results of tests performed regarding features of fabrics believed to be related to the hand of textiles. Such quantified results are in some cases quite far from the real perception of fabrics by humans. To verify those objective tests, scientists compare them with tests performed with the participation of the group of people, experts or naïve users or both. Such activity allows verification of both sets of results, identification of the divergences, and analysis of the source of these divergences, their scale, and so on. It also creates the possibility for other developments in the area of hand analysis.

Some studies have reported a good correlation between subjective finger-pressure assessments of the fabric softness and compression at low pressures. ⁶⁰ This study also confirms the uncertainty about the words used to describe handle. Some descriptive words appear to have multiple meanings. Softness changes its meaning in relation to the fabric being handled. It is also believed that the selection of sets of fabrics matters when the subjective analysis is to be compared with objective analysis ⁶¹ using objective measurements of compression.

The sensation of warmth or coolness to touch when skin is brought into contact with a fabric is a transient heat conduction phenomenon and contributes to the perception of comfort of a garment. Skin brought into contact with the surface of a garment is normally at a higher temperature than the garment, and heat flows away from the skin. It has been proved that the coolness rating can be correlated with the thickness of the external layer of the textiles (if there is a layer-package). ⁶²

One of the general remarks presented in the studies related to the smoothness, friction, and handle is that even if, objectively, fabrics offer similar frictional resistance to motion and possess similar coefficients of friction, subjectively, that is, tactually, these fabrics may be different or similar. ⁶³

A summary of the relationships between sensory and mechanical properties of fabrics was made in a wide ranging review by Bishop. ⁶⁴ He applied a term fabric objective measurement (FOM) while presenting subjective evaluations versus objective measurements. He stated that the subjective evaluation of fabrics should be based on psychophysical measurements of fabric attributes that give reasonably consistent results from one individual to another. Finally, he discussed the Weber-Fechner law and Stevens’ power law to translate instrumental measurements of fabric mechanical properties into corresponding hand parameters. The author also presented a few scales/descriptor categories for handle that have been adapted successfully to many contemporary studies. ⁶⁴ One of the key issues mentioned in his work refers to skin interactions with perception of comfort in clothing. Interactions between clothing and the body can be transferred to tactile perception of textile quality, which overlaps with the subjective evaluation of fabric handle. This raises an interesting issue. It is believed that one can estimate the handle subjective features based on subjective comfort evaluation, however, the most interesting issue is to be able to predict subjective comfort evaluation having handle subjective features or handle objective parameters.

Comfort aspects have been widely discussed in another study ⁶⁵ in relation to the perception of fabric hand. There is a fundamental difference between the perception of touch by wearing a garment and by handling a fabric. Touch is passive in the case of wearing the garment, the wearer does not move intentionally to receive information concerning the garment, which is collected through the skin surface. Touch is active in the case of handling of the fabric. The user moves the hand to obtain information concerning the fabric. Two other divisions of touch are postulated. Firstly, Heller et al. ⁶⁶ refer to synthetic touch, which is used to obtain an overall impression by a resting hand and analytic touch, which is used to obtain exhaustive information about the object being touched. Secondly, Katz ⁶⁷ classifies the active touch into four classes: 1) gliding touch – short motions to obtain information about the surface; 2) sweeping touch – fingers check the general conditions and contours; 3) grasping – global and complete touch but also comparing the surfaces; 4) kinematic touch – comprehensive analysis of an object.

Alternative solution

According to the authors of this paper, to come closer to an idealized system of measuring the hand of textiles, the creation of an artificial system that works like a natural sense organ is required. In the case of the hand of textiles this organ is the skin of the hand of each person in which the perception system exists. We propose an alternative solution to the existing, non-ideal objective and subjective systems of hand measurements. The idea is to create a model of the fingertip skin section that possesses all mechanoreceptors to detect objects that are in contact with it. This application of mechanical principles to biological systems such as humans, animals, plants, and organs is called biomechanics. Mechanical deformation of hard tissues (like wood, shell, and bone) may be analysed with the theory of linear elasticity. On the other hand, soft tissues (skin, tendon, and muscle) undergo large deformations and thus their analysis relies on the finite strain theory and computer simulations. ⁶⁸

We propose a biomechanical approach as a novelty in the measurement and analysis of the hand of textiles. The rationales for this approach are:

a possibility of mimicking the skin sense organ with a high precision;

A large amount of studies regarding hand or human skin modelling have been carried out. They are mainly related to medical applications, for example prosthesis creation, modelling of the ageing process of the skin, collagen fibre analysis, and neurological studies.

The creation of a three-dimensional model of the human skin, by application of the finite element method, to gain a deeper understanding of the human sense of touch in reference to textiles is the new approach.

Two cube-like solids are presented in Figure 1 and in detail, showing a coarse meshed model of a fingertip skin section of 10 mm length × 9 mm width × 6 mm height. The mechanical parameters of the skin which were applied to this model are the Young modulus: 136 kPa for the epidermis, 80 kPa for the dermis, and 34 kPa for the hypodermis, and a Poisson’s ratio of 0.48 for all skin layers. ⁶⁹ A uniform distribution of 1 N loading was applied on the top of the skin section. So the model was deformed, which can be observed in Figure 1b.

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Figure 1.

Finite element computation of the stress in meshed model of the fingertip skin section: (a) meshed without loading, (b) meshed with a uniform distribution of loading of 1 N placed on the top of the section (authors’ own studies).

It is believed that skin presents hyperelastic mechanical properties, however, neither non-linearity nor more advanced stress–strain analysis of nodes has been applied as the study is at a very early stage.

It has already been noticed that the highest deformation exists in the centre of the model.

Stress causing a deformation refers to the textile object having contact with the skin of the fingertip. Strain reflects a deformation that has been done to the skin by the textile. Basic stress–strain analysis could answer the question of what kinds of textiles have contact with the skin. There is a question of realism of the model. The more detailed the model, the more accurate the results are, and consequently a better estimation of textile features is possible. It is estimated that the presented model is far from reality at this initial stage as it does not take into account a full geometry of the fingertip skin section, for example fingerprint lines, curvature of the fingerpad skin, and equilibrium equations noted to all nodes playing the role of mechanoreceptors in the model, with the irregularity of distribution of these nodes reflecting mechanoreceptors.

This branch is relatively new for the analysis of the relation between textiles and humans; however, it seems to be extremely promising.

Hand measurement techniques

On the basis of the literature review and the authors’ own studies, a simplified division of hand measurement techniques is presented (Figure 2). There are four main techniques to quantify fabric hand: objective techniques; subjective techniques; a combination of objective and subjective techniques; and finally, mathematical and biomechanical modelling.

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Figure 2.

A simplified division of contemporary hand measurement techniques according to the literature review and the authors’ own studies.

Due to obvious limitations, the authors could not describe all aspects of the proposed division in detail. It is believed that neurophysiological tests already applied or potentially applied to textiles, gesture and finger motion analysis, mathematical modelling and virtual haptic perception could be analysed in further reviews.

The neurological tests refer to neural response of skin receptors. ⁷⁰ Receptors of the skin are stimulated to evoke stimuli. They used to be analysed by devices such as an electromagnetic instrument by von Frey. This is a well known device developed in 1923 that enabled one to apply tiny stimuli to the skin. It consisted of a series of brushes of different degrees of stiffness which were fixed with sealing wax to a moveable rod. This instrument, was used to locate pain points and to determine their threshold values. Contemporary methodologies, e.g. functional magnetic resonance imaging, can indicate the actual activity of cortex ⁷¹ to present sensorial reaction of the brain on tactile signals from the fingertips.

An example of finger motion analysis for evaluation of the hand is a glove-type system. ⁷² Authors used it together with pressure sensors to analyse finger motions during the textile evaluation process. The sensors provided data concerning applied force and finger motion. The results proved the finger motion of experts is better suited to sensory evaluation.

A great development of virtual techniques relates also to textiles, especially visualization of fabrics for purchase via the internet. ⁷³ Providing the sensation of touch of digital textiles significantly increases the realism and believability of the user experience. Tactile characteristics of virtual textiles while interacting with them via computer tools introduces a brand new way of assessing the specific surface and material properties of 3-D objects representing real products. ⁷³ Tools like this are not strongly popularized yet. A good example of such product is a system developed by EST – Engineering Systems Technologies GmbH & Co. KG. ⁷⁴ The SensAble Technologies PHANTOM® product line of haptic devices developed by EST makes possible for users to touch and manipulate virtual objects.

Conclusions

There is a great diversity of contemporary techniques of objective hand measurements. Although they present different approaches they basically aim to analyse the same physical parameters of fabrics that are believed to be related to the so-called hand of textiles. It appears that apart from improvement of the accuracy of measurement and precision of instruments, no further meaningful advancement can be made in relation to the physical features of textiles and the appropriate features and attributes of the hand of textiles, e.g. ring method test. ³⁶