Assessment of Fabric HandAssessment of Fabric Hand

Dr. Jimmy LamDr. Jimmy Lam

Institute of Textiles & ClothingInstitute of Textiles & Clothing

Learning ObjectivesLearning Objectives

What is fabric hand and how to make What is fabric hand and how to make assessment of fabric hand?assessment of fabric hand?

FOUR conditions to access fabric hand, they FOUR conditions to access fabric hand, they are: 1) the judge; 2) judgement criteria; 3) are: 1) the judge; 2) judgement criteria; 3) assessment conditions and 4) ranking methodassessment conditions and 4) ranking method

IntroductionIntroduction

One of the important attributes used in the textile and One of the important attributes used in the textile and apparel supply chain is fabric handle.apparel supply chain is fabric handle.

Evaluation of fabric quality has traditionally been Evaluation of fabric quality has traditionally been assessed subjectively in both textile and clothing assessed subjectively in both textile and clothing industries.industries.

The simplest and most widely used method of The simplest and most widely used method of subjectively assessing fabric quality is through the subjectively assessing fabric quality is through the notion of fabric handle.notion of fabric handle.

Subjective AssessmentSubjective Assessment

How reliable is this kind of judgement?How reliable is this kind of judgement? Can they reproduce the same results?Can they reproduce the same results? How they made this judgement (says good, How they made this judgement (says good,

average or bad)?average or bad)? Can we reproduce the same results by a Can we reproduce the same results by a

machine (objective judgement) ?machine (objective judgement) ?

Fabric Hand - DefinitionFabric Hand - Definition The term hand has been defined as “the subjective The term hand has been defined as “the subjective

assessment of a textile material obtained by the sense of assessment of a textile material obtained by the sense of touch.touch.

Hand is thus a physiological and psychological Hand is thus a physiological and psychological phenomenon.phenomenon.

It implies the ability of the fingers to make a sensitive and It implies the ability of the fingers to make a sensitive and discriminating assessment and of the mind to integrate discriminating assessment and of the mind to integrate and express the results in a single valued judgement.and express the results in a single valued judgement.

Such a judgement cannot be obtained objectively, since Such a judgement cannot be obtained objectively, since the relevant mechanism of the sensory organs, the the relevant mechanism of the sensory organs, the nervous systems, and the brain are not known and vary nervous systems, and the brain are not known and vary from individual and also with time for each individual.from individual and also with time for each individual.

Fabric HandleFabric Handle Fabric handle is, therefore, not really a property in Fabric handle is, therefore, not really a property in

itself; rather it is a very complex compilation of all itself; rather it is a very complex compilation of all fabric properties which can be assessed by human fabric properties which can be assessed by human touch.touch.

Fabric may be assessed as having superior handle for Fabric may be assessed as having superior handle for a variety of reasons.a variety of reasons.

For example, the fabric may have good tailoring For example, the fabric may have good tailoring properties, comfort, various aesthetic qualities and properties, comfort, various aesthetic qualities and drape.drape.

Subjective assessment of fabric Subjective assessment of fabric handhand

Four ConditionsFour Conditions Four steps involved in the subjective hand Four steps involved in the subjective hand

evaluation with particular reference to use of the evaluation with particular reference to use of the results in Fabric Objective Measurement (FOM) results in Fabric Objective Measurement (FOM) systems are:systems are:

1.1. The judges, in particular their expertise and cultural The judges, in particular their expertise and cultural backgroundbackground

2.2. The criteria of judgement, the choice of descriptors The criteria of judgement, the choice of descriptors for fabric attributesfor fabric attributes

3.3. The assessment conditions, fabric seen or unseen, The assessment conditions, fabric seen or unseen, controlled temperature and relative humiditycontrolled temperature and relative humidity

4.4. The method of ranking or scaling the assessment.The method of ranking or scaling the assessment.

Condition#1 JudgementCondition#1 Judgement

Who makes better judgement? Someone with Who makes better judgement? Someone with ten years experiences working in textile ten years experiences working in textile industry or a fresh graduate from university.industry or a fresh graduate from university.

In order word, can an expert make better In order word, can an expert make better judgement than non-expert ?judgement than non-expert ?

Binns ExperimentBinns Experiment

In the earliest work on subjective hand evaluations, In the earliest work on subjective hand evaluations, Binns (1926, 1934) investigated the effect of judges’ Binns (1926, 1934) investigated the effect of judges’ technical and sociological backgrounds on the ranking technical and sociological backgrounds on the ranking in various fabric samples.in various fabric samples.

In one study, Binns (1934) used two panels of judges In one study, Binns (1934) used two panels of judges comprising:comprising:– 22 experienced manufacturers and buyers of fabric similar to 22 experienced manufacturers and buyers of fabric similar to

those used in the tests;those used in the tests;

– Six teenage boys of mixed abilitiesSix teenage boys of mixed abilities

Binns Experiment Binns Experiment ResultsResults

ResultsResults These judges were asked to rank two groups of fabrics in These judges were asked to rank two groups of fabrics in

order ranging from “best” to “worst” hand, without any order ranging from “best” to “worst” hand, without any instruction on what fabric attributes to look for.instruction on what fabric attributes to look for.

These two groups of fabrics each consisted of the same six These two groups of fabrics each consisted of the same six fabrics, but one group had a “clear” finish whereas the other fabrics, but one group had a “clear” finish whereas the other group had been milled.group had been milled.

The Sperman rank correlation coefficient between expert The Sperman rank correlation coefficient between expert and boys’ ranking is 0.73 for the milled finish and is 0.95 for and boys’ ranking is 0.73 for the milled finish and is 0.95 for the clear fabric.the clear fabric.

Binns concluded that “ while the tactual or handle judgement Binns concluded that “ while the tactual or handle judgement appears to be native and immediate, it does not imply that appears to be native and immediate, it does not imply that any person is qualified to buy or sell textiles, there are many any person is qualified to buy or sell textiles, there are many other factors to be considered.”other factors to be considered.”

What weave makes the strongest What weave makes the strongest fabric?fabric?

Condition#2 Condition#2 Criteria of JudgementCriteria of Judgement

Having decided who makes the judgement Having decided who makes the judgement (expert in textile area or non-expert), what are (expert in textile area or non-expert), what are the criteria of judgment?the criteria of judgment?

Is it good enough to say, the fabric is “GOOD” Is it good enough to say, the fabric is “GOOD” or “BAD”.or “BAD”.

If not, what else we should look for ?If not, what else we should look for ?

Fabric DescriptorsFabric Descriptors

Howorth and Oliver used a panel of 25 laboratory Howorth and Oliver used a panel of 25 laboratory assistants with no special experience in handling assistants with no special experience in handling fabrics, to rank 27 samples of worsted suiting fabrics.fabrics, to rank 27 samples of worsted suiting fabrics.

All descriptive terms and their frequency of use were All descriptive terms and their frequency of use were shown in Table 2.2. shown in Table 2.2.

It was found that 86% of all decisions were made on the It was found that 86% of all decisions were made on the basis of the nine most frequency used descriptors.basis of the nine most frequency used descriptors.

David used “bipolar descriptors” to qualify the fabric as David used “bipolar descriptors” to qualify the fabric as shown in Table 2.3shown in Table 2.3

Criteria of JudgmentCriteria of Judgment

Covered86%

HESC StandardHESC Standard Kawabata and Niwa (1989) generated fabric descriptors Kawabata and Niwa (1989) generated fabric descriptors

through discussion with a panel of expert judges in Japan, through discussion with a panel of expert judges in Japan, the Hand Evaluation and Standardization Committee the Hand Evaluation and Standardization Committee (HESC) in the context of specific fabric end uses.(HESC) in the context of specific fabric end uses.

Kawabata reported that initially the expert did not recognize Kawabata reported that initially the expert did not recognize that they evaluated fabric quality (total hand value) on the that they evaluated fabric quality (total hand value) on the basis of a number of specified properties.basis of a number of specified properties.

However, when the experts were questioned as to the However, when the experts were questioned as to the reasons for selecting one fabric rather than another, the reasons for selecting one fabric rather than another, the Japanese judges always replied on fabric attributes in terms Japanese judges always replied on fabric attributes in terms of smoothness, stiffness and crispness.of smoothness, stiffness and crispness.

Kawabata called these descriptors “Primary hand value”.Kawabata called these descriptors “Primary hand value”. Figure 4.1 shows the Primary Hand Value and Total Hand Figure 4.1 shows the Primary Hand Value and Total Hand

Value defined by KawabataValue defined by Kawabata

Condition#3 Condition#3 Evaluation ConditionsEvaluation Conditions

The term “hand” defined by the Textile Institute as “the The term “hand” defined by the Textile Institute as “the subjective assessment of a textile material obtained subjective assessment of a textile material obtained from the sense of touch” is somewhat vague to allow its from the sense of touch” is somewhat vague to allow its evaluation in either “seen” or “unseen” conditions.evaluation in either “seen” or “unseen” conditions.

The systematic evaluation of handle, based on a The systematic evaluation of handle, based on a definition that is specific to the sense of touch, might be definition that is specific to the sense of touch, might be expected to involve taking precautions to exclude bias expected to involve taking precautions to exclude bias caused by fabric appearance and possibly even by fabric caused by fabric appearance and possibly even by fabric odour and also any rustling sound made by some odour and also any rustling sound made by some fabrics.fabrics.

Evaluation ConditionsEvaluation Conditions

Should fabric be assessed by “touch” only or “sight-Should fabric be assessed by “touch” only or “sight-and-touch” together?and-touch” together?

The work of Hallos (1990) concluded that “sight-and-The work of Hallos (1990) concluded that “sight-and-touch” approach was of a higher order than tactile touch” approach was of a higher order than tactile perception.perception.

It therefore, might be expected that visual perception It therefore, might be expected that visual perception only, and visual and tactile perception together, should only, and visual and tactile perception together, should afford greater discrimination between fabrics than afford greater discrimination between fabrics than touch alone.touch alone.

Condition #4Condition #4Ranking fabric attributeRanking fabric attribute

How do we rank the fabrics? (Good or bad)How do we rank the fabrics? (Good or bad) If we want to compare one sample with others, If we want to compare one sample with others,

the ranking must be scaled to certain standard.the ranking must be scaled to certain standard.

Ranking samplesRanking samples

Subjective assessment of fabric properties that Subjective assessment of fabric properties that are intended for correlation with objective are intended for correlation with objective measurements must be scaled in some way.measurements must be scaled in some way.

The work developed by Kawabata (1982, 1989), The work developed by Kawabata (1982, 1989), in celebration with Japanese HESC, provided a in celebration with Japanese HESC, provided a set of commercially available primary hand set of commercially available primary hand standards, representing a full range of quality standards, representing a full range of quality attributes for this scaling purpose.attributes for this scaling purpose.

Ranking of Primary Hand and Total Hand Value

Summary (1)Summary (1)

Assessment of Fabric Hand is complex process.Assessment of Fabric Hand is complex process. The definition of fabric hand and evaluation The definition of fabric hand and evaluation

process are not yet defined properly.process are not yet defined properly. Four criteria are needed to access fabric hand Four criteria are needed to access fabric hand

properly, they are 1) the judges; 2) judgement properly, they are 1) the judges; 2) judgement criteria; 3) assessment condition and 4) ranking criteria; 3) assessment condition and 4) ranking method.method.

Summary (2)Summary (2)

It was found expert judges and non-expert judges cannot It was found expert judges and non-expert judges cannot distinguish textile fabric completely based on fabric hand distinguish textile fabric completely based on fabric hand alone.alone.

However, results from expert judges make less variation However, results from expert judges make less variation (or degree of fluctuation) than non-expert judges.(or degree of fluctuation) than non-expert judges.

The judgement criteria are normally based on Kawabata The judgement criteria are normally based on Kawabata Primary Hand and Total Hand ValuePrimary Hand and Total Hand Value

The assessment conditions are normally based on “Sight-The assessment conditions are normally based on “Sight-and-touch” as they are most commonly used in the and-touch” as they are most commonly used in the industry.industry.

The ranking method is normally based on HESC as a The ranking method is normally based on HESC as a standard is established for comparison directlystandard is established for comparison directly