The influence of textiles' sensorial information on the perception and preference of sport clothing

Comfort is a fundamental attribute of life. Every person is constantly trying to improve or maintain their optimum comfort level, consciously or involuntarily with the help of the body’s thermoregulatory system and the support of textile products. It is easy to define discomfort such as pain, itch or excessive warmth to a person who immediately understands the nature of the problem, however, it is difficult to give a quantitative definition of comfort due to its subjectivity. It is impossible to measure comfort as a total state of mind or body, but possible to assess factors relating directly or indirectly to comfort.

The properties that enable textile products to be versatile include psychological, physical and physiological parameters (Slater, 1986). Many studies have been conducted in the textile- clothing research area investigating physiological and psychological comfort as well as mechanical, thermal, and surface testing for the evaluation of objective properties of garments, however, the connection to consumer feelings is difficult to establish. There are multiple facets of fabric hand that are not well understood yet and the area of the physical/tactile comfort still needs consideration (Das & Alagirusamy, 2010). Therefore, this thesis aimed to investigate comfort and haptic perception in textiles and further give resourceful insights into the less researched area of the three comfort P’s – the physical/tactile comfort.

Assumptions on clothing comfort from the reviewed literature are well known, however, the first question arising is if this is following with what consumers understand about clothing comfort. An online questionnaire was developed to lay foundations for expectations, perceptions, and preferences on clothing comfort of sports garments from a consumer’s point of view, and to investigate underlying factors of purchase (study 1).

This online survey comprised 292 respondents, classified by sex, age, nationality, and physical activity. Fit and comfort are closely linked together, both forming part of the clothing comfort concept. When purchasing garments online, the haptics of fabrics was identified as a crucial missing parameter. However, priorities of attributes within the concept varied according to the person’s sex and nationality. Females put more emphasis on garment fit and showed higher need for tactile input, whereas males prioritised physiological comfort descriptors, i.e., properties which facilitate thermoregulation. Sex and nationality are parameters modulating the clothing comfort concept and the conceptualised feel of materials. Therefore, sex and nationality of the end consumer should be considered during the development phase of sports garments, and particular attention should be given to the targeted market in which these will be sold.

The results of the survey led to explore the lack of sensorial input in the e-commerce domain which impairs consumers’ online apparel purchases. On this premise, the second study investigated how visual interpretation of the feel of fabrics is related to the actual feel of fabric samples and whether humans can perceive haptic properties solely through the sense of sight (online). Haptic textile attributes of seven selected fabric swatches were quantified in an online questionnaire showing squared and draped textile images (part I) and in a physical fabric assessment of samples mailed to participants, guided through Microsoft Teams (part II). The comparison of the visual only and the visual-haptic assessment showed statistically significant differences, i.e., higher variability and lower scores on the scale of the haptic attributes in the visual only session. Especially textile surface structure related haptic attributes (e.g., rough, smooth, silky) could not be conveyed visually and needed tactile sensory input to assess. No robust significant differences were found between male and female responses.

To critically assess the methodology used in this non-laboratory-based/practical approach, the next study was drawing a comparison with a controlled laboratory environment. The developed protocol for evaluating haptics in textiles was further tested for repeatability and reliability. Possible changes in haptic perception and preferences throughout the female menstrual cycle were also taken into consideration (study 3), since it is known that the cycle has an impact on physiological and psychological (comfort) changes but not known if it influences the physical/tactile perception and preferences. Participants evaluated the same textile swatches by using an adapted haptic protocol of the previously conducted study in three identical sessions. The trials of the female participants were scheduled across the menstrual cycle (menses, follicle, luteal phase). No statistical differences were found in the repeated sessions in male or female participants. The menstrual cycle did not have any influence on the haptics perception or preference of materials. Furthermore, no differences were found in the quantitative measured data across the three sessions (anthropometrics, skin hydration, skin and aural temperature, and hand sensitivity). The comparison of a non- laboratory-based set-up to a laboratory-based environment showed good agreement and is, therefore, a feasible and novel method to assess haptics in textiles. The established repeatable and reliable subjective approach to textile appraisal is a valuable addition to the physical objective properties of textile materials and key to creating predictive relationships between tactile attributes of the fabric and perceived preferences, which was investigated in the next study (study 4).

The study aimed to explore the physical properties of textiles and identify their relationship with tactile perception. Eight physical textile tests (Emtec haptic analyser, 3D-Profilometer, C- Therm, Thermal hot plate, Air permeability, Thickness, Weight, Tensile testing) were performed to characterise the seven selected textiles. Correlations between the mechanical properties and 18 hand sensations (e.g., rough, smooth, natural, synthetic, etc.) showed that subjective qualities such as breathability, thickness, weight, stretchability, stiffness, flexibility can be connected to and predicted by at least one objective laboratory tests; however, sensations of the surface roughness, softness, and fibre type failed to correlate. Regression models were established to understand the strength and form of the predicted relationships. Objective threshold values for perceptual textile characteristics were created with appropriate regression models. The established models for breathable, thick/thin, warm/cold, heavy/lightweight, stretchable, stiff, and flexible can be predicted with a high percentage of reliability (above 70 % of explained variation).

The final study involving human participants was looking at the hand-feel of materials but from a whole-body perception perspective, specifically of sports garments (study 5). The feel of garments during a passive activity (i.e., no physical activity - simulating a shop-like setting), and comfort characteristics during physical activity were investigated. Next-to-skin sportswear (t-shirts) made from three different fibre types (cotton, polyester I, polyester II) was studied in a hand, donning (pre-purchase) and running evaluation (post-purchase). Throughout the protocol, objective measurements, and perceptual responses to 13 hand- /skin-feel descriptors were recorded. Furthermore, the three most important haptic attributes contributing to a purchase decision were asked in the hand, donning, and running assessments.

No significant perceptual differences between a hand and a donning evaluation were found in the rating of the sensations. The hand evaluation provided sufficient information for a comfort response to garment wear. The pre- and post-purchase comparison found a significantly lower perception in roughness, smoothness, and restriction to movement and a significantly higher perception of stickiness. With the accumulation of moisture on the skin during running, haptic sensations, especially regarding the surface of fabrics, changed. The cotton fabric was perceived significantly different to the two polyester fabrics in all attributes. Comparing the most important attributes relevant to forming an opinion about a garment pre- and post-purchase, it was found that physical comfort descriptors (e.g., smooth) are more important pre-purchase, whereas physiological comfort descriptors (e.g., breathable) gained importance post-purchase.

This thesis aimed to identify reliable subjective measurements within the human- environment-clothing system to measure the hand- and skin-feel of textile materials to improve sports products and enhance utility. However, not only should these investigations affect manufacturers but also consumers. Informing consumers about clothing comfort will contribute to their decision-making process and in the end influence their purchase behaviour.