Black/White Stripe Used for Sportswear

Transcription

1 A Study of Visual Effect of Black/White Stripe Used for Sportswear T.Tokuyama*, C.Mizutani**, M.Kamijo***, T. Sadoyama*** and Y. Shimizu*** *Faculty of Home Economics, Gif u Women's University, **Faculty of Human Life and Environment, Heian Jogakuin(St.Agnes') University, ***F aculty of Textile Science and Technology Shinshu University, An experimental study was conducted to examine how people feel and judge the apparent length and slimness of legs wearing sportswear with stripy designs, and to identify what type of stripy designs for sportswear provides visual effects making legs appear longer and slimmer. Consequently, the sample without stripes on a white background was rated short and thick while all the samples with stripes on white backgrounds were rated rather long and slim, proving that a geometrical illusion effect can be obtained by arranging black stripes on a white background. Furthermore, the test results showed that increasing the thickness and number of stripes on either a white background or a black background would make legs appear to be longer and that increasing the thickness of stripes on a white background would make legs appear slimmer, and a black background itself even without stripes would have an effect of compacting the appearance and making the legs appear rather slim. Among the white-background samples, g2 stripe of 6mm thickness h, g3 stripe of 10mm thickness hand g1 stripe of 25mm thickness hwere rated for making legs appear long and slim. Among the black-background samples, the g3 stripe of 10mm thickness hsample was rated for making legs appear long and slim. (Received June 24, 2002) Key Words: visual effect, stripe of sportswear, geometrical illusion effect, paired comparison. (Journal of the Japan Research Association for Textile End-Uses, Vol. 43, pp , 2002)

2 1. Introduction Sportswear has recently become diversified in design, color, material, etc. Athletes prefer sportswear of better functionality and/or better design among the various selections. The design of sportswear is especially important for athletes participating in athletic events that require visual and with stripes arranged partially on it. Moreover, there have been no reports on studies on how human visual perception is affected by clothes with designs of stripes. The purpose of this study was to examine how human visual perception of the length and thickness of legs is affected by variations in the thickness and number of psychological elements. With regard to the issue of design, most sportswear has stripes on the sides, and it is conceivable that such designs utilize a stripes, and to identify the types of stripedesigns for sportswear that provide visual effects making legs appear longer and slimmer. geometrical illusion effect to make legs appear longer and slimmer. Recently the number, color and thickness of such stripes vary from design to design. Now people have put on sportswear as casual wear in their daily life as well as in sport. It seems that because of this phenomenon people have grown to ask both function and design for sportswear. Attempts to examine the design of striped patterns have become widely known through studies of designs utilizing geometrical illusion effects. For example, we know of popular theories of striped patterns, such as that gvertical stripes show objects longer and slimmer, and horizontal stripes show objects shorter and wider h1 `3).On the other hand, we know about Helmholtz's square, showing a reverse geometrical illusion effect; vertical stripes rather make squares appear horizontally wide, and horizontal stripes rather make squares appear vertically long4).such conflict between these two theories can be considered to have resulted from the two different test methods, that some tests were done with samples being worn and others by planar samples, such as stripes drawn on a level. Although there have been many studies on the visual effects of clothes with striped patterns, no study has been conducted on sportswear 2. Methods 2.1 Stimulus The samples utilized for judgment were six types each for gblack stripes on a white background h and gwhite stripes on a black background h. The six types of gblack stripes on a white background hare: gplain white without stripes (called Plain) h, g1 stripe of 3mm thickness h, g2 stripe of 3mm thickness h, g2 stripe of 6mm thickness h, g3 stripe of 10mm thickness hand g1 stripe of 25mm thickness h. The other six types of g white stripes on a black background hare: g plain black without stripes (called Plain) h, g1 stripe of 3mm thickness h, g2 stripe of 3mm thickness h, g3 stripe of 10mm thickness h, g2 stripe of 15mm thickness h and g1 stripe of 25mm thickness h. All of this is merchandise of 100% polyester. Yxy of the white and black colors on each background are shown in Table 1, being measured by a Colorimeter Meter (MINOLTA CR-200b). Each of the samples was fitted on T-shirt of gray and sportswear form placed by a north window under the daylight for photographs, which were taken from the side and at 45-degrees diagonally to the front of the form so that virtually practical images of the samples could be viewed from the photographs. The dimensions of the

3 Table 1,Yxy colorimetric values of sample colors White cloth 2.3 Test Methods Two photographs consisting of the side view and the 45-degree diagonal front view per item of sportswear were utilized as a single set of test samples. Placing sampleset I and sample-set II on the table, the subjects evaluated the length-impression of set I against that of set II. Evaluations of slimness-impression were made in the same way. There were fifteen combinations of sample-sets for each judgment category, as no consideration was taken for the effect photographs were made uniform digitally of order throughout this paired comparison by computer. test. 2.2 Judgments Judgments were made according to four categories; the length-impression of a white background, the slimness-impression of a white background, the length-impression of a black background and the slimnessimpression of a black background. The twelve samples were judged by abovementioned categories and evaluated according to a seven-grade system for performing a paired comparison test. Since reciprocation comparison were allowed, each subject in the test made every comparison without considering the order of comparison. The evaluation grades were, with regard to the 2.4 Statistical Analysis In order to examine whether the subjects had felt different impression of the length and slimness between the compared sportswear, from the results of sensory evaluations obtained by the paired comparison method an analysis of the variance was performed with Haga's modification the length-impression and the slimnessimpression of sportswear for each of 4 judgment categories5). The six kind of relative length and slimness impression for each sample is represented by a respective hedonic scale of averages determined using the equation(1)below. Compared with gt h length-impression: gvery short h, gfairly samples, the comparison were performed short h, gslightly short h, gno difference h, every gn htimes randomly. h slightly long h, gfairly long h and gvery long h. In regard to the slimness-impression they were gvery thick h, grather thick h, h slightly thick h, gno difference h, gslightly slim h, grather slim h and gvery slim h. The rating points assigned to each grade were from -3 to +3, following the above sequence. The subjects were 180 female university students of 18 to 22 years. Hedonic scale of averages c(1) Where: t=the number of samples n=the number of comparison Deviations from subtractivity (2) Formulas for calculating the sum of squares of each effect are as follows:

4 the length-impression from a white background, the slimness-impression from a The degree of freedom is the main effect of( Sƒ ); t-1 and the deviation from subtractivity of (SƒÁ); (t-1) (t-2)/2. The confidence interval (ƒ i-ƒ j) is derived when the main effect resulting from the analysis of variations has been significant, and then the ƒ 1-interval with difference is verified. The yardstick Yƒ is calculated by the following equation. c (5 ) The confidence interval is found by the following equation: c (6) 3. Results 3.1 White background: length-impression and slimness-impression Based on the data concerning the judgments on glength-impression from a white background h, gslimness-impression from a white background h, glength-impression from a black background h and gthe slimnessimpression from a black background h, a variance analysis was performed to examine whether variations in the thickness and the number of stripes had affected the lengthimpression and the slimness-impression (Table 2). As a result, the main effect was highly significant by 5% with judgments of white background, the length-impression from a black background and the slimnessimpression from a black background. Additionally, the deviation from subtractivity was significant for all judgments except the slimness-impression from a white background. Those results showed that the subjects had made judgments on the lengthimpression and slimness-impression corresponding to variations in the thickness and number of stripes on the sportswear. Respective results of the judgments of the length-impression and slimness-impression from a white background are shown in Fig. 1. On the horizontal axis is a hedonic scale of averages as a yardstick indicating values of the length-impression corresponding to the variations in thickness and number of stripes on the sportswear. On the vertical axis is a hedonic scale of averages as a yardstick indicating values of the slimnessimpression corresponding to the same. Epithets for the horizontal axis are glong h and g short h; the higher the value rises toward 0.4, the more sensible of glong h the impression is, and the more the value decreases toward -0.4, the more sensible of gshort h the impression is. Epithets for the vertical axis are gslim h and gthick h; the more the value rises toward 0.4, the more sensible of g slim hthe impression is, and the more the value decreases toward -0.4, the more sensi- Table2. F value of main effect deviations from subtractivity in method ( g* hshows being significant at 0.05 level of significance.)

5 Fig.1 Hedonic Scale of Average in length and slimness-impression by White background Fig.2 Hedonic Scale of Average in length and slimness-impression by Black background ble of gthick h the impression is. and slimness-impression All of the samples of sportswear with lines were judged rather longer and slimmer than the Plain samples. With regard to the length-impression from a white background, g2 stripe of 3mm thickness h, g2 stripe of 6mm thickness h, g3 stripe of 10mm thickness hand g1 stripe of 25mm thickness hare on the plus (+) side (judged glong h), but Plain and g 1 stripe of 3mm thickness hare on the minus (-) side (judged gshort h). With regard to the slimness-impression from a white background, g2 stripe of 6mm thickness h, g3 stripe of 10mm thickness h and g1 stripe of 25mm thickness hare on the plus (+) side (judged gslim h), but Plain, g 1 stripe of 3mm thickness hand g2 stripe of 3mm thickness h are on the minus (-) side (judged gthick h). As a result, g2 stripe of 6mm thickness h, g 3 stripe of 10mm thickness hand g1 stripe of 25mm thickness hwere recognized to make legs appear long and slim while Plain and g1 stripe of 3mm thickness hwere recognized to make legs appear short and thick. Respective results of the judgments for the length-impression and slimnessimpression from a black background are shown in Fig. 2 with the same axis configuration as Fig. 1. With regard to the length-impression from a black background, g2 stripe of 3mm thickness h, g3 stripe of 10mm thickness h, g2 stripe of 15mm thickness h and g1 stripe of 25mm thickness h are on the plus (+) side (judged glong h), but Plain and g1 stripe of 3mm thickness h are on the minus (-) side (judged gshort h). With regard to the slimness-impression from a black background, Plain and g3 stripe of 10mm thickness h are on the plus (+) side (judged gslim h), but g1 stripe of 3mm thickness h, g2 stripe of 3mm thickness h, g2 stripe of 15mm thickness hand g1 stripe of 25mm thickness h are on the minus (-) side (judged gthick h). Plain was rated rather short and slim. g1 stripe of 3mm thickness h, g2 stripe of 3mm thickness h, g2 stripe of 15mm thickness h and g1 stripe of 25mm thickness hwere rated rather long and thick compared with Plain, and g3 stripe of 10mm thickness h 3.2 Black background: length-impression was rated rather long and slim compared

6 with Plain. As a result, g3 stripe of 10mm thickness h was recognized to make legs appear long and slim while g1 stripe of 3mm thickness h was recognized to make legs appear short since the plain white was rated the gthickest h. Among the samples with stripes, the stripes of 3mm thickness, regardless of the number, was rated the gthickest h, and the 6mm-thickness, the 10mm-thickness and the and thick. 25mm-thickness stripes were rated slim, proving that stripes-thickness affected the 4. Examination 4.1 White background: length-impression slimness-impression and increasing the thickness made legs appear slimmer. and slimness-impression It is conceivable that the samples with With regard to the visual effects of sportswear designs with arrangements of stripes, it has been proved that a geometrical illusion effect can be obtained by arranging black stripes on a white background, since all the samples with black stripes on a white background were rated rather long and slim while Plain was rated short and thick. This suggests that the plain white was rated thick since white is an expansive color, just as in the color appearance phenomena in which a bright wide stripes and numbers of stripes affected human impression since g2 stripe of 6mm thickness h, g3 stripe of 10mm thickness h and g1 stripe of 25mm thickness h were recognized to make legs appear long and slim. And then, Plain and g1 stripe of 3mm thickness hwere recognized to make legs appear short and thick. Therefore, it should be considered that a stripe extremely narrow in thickness worked ineffectively and was rated short and thick the same as Plain. color appears large and a dark color appears small. And the results of black 4.2 Black background: length-impression stripes on a white background agree well and slimness-impression with the popular theory of striped patterns which states that vertical stripes show things longer and slimmer. It is conceivable that the strong contrast of black stripes on an expansive white background makes legs appear long while black stripes provide an effect of and making the legs appear With regard to the length-impression from a black background, it should be considered that the stripes affected human impression since the plain black was rated the g shortest h. The result particularly indicates just as in the case of the length-impression from a white background that increasing compactand slim. the thickness and the number of stripes With regard to the length-impression from a white background, it should be considered that the stripes affected human impression since the plain white is rated the g shortest h. The result particularly indicates that increasing the thickness and number of stripes made legs appear longer. With regard to the slimness-impression from a white background, it should be considered that the stripes affected human impression made legs appear longer. With regard to the slimness-impression from a black background, the black background itself was proved to have an effect of making the appearance compact even without stripes on it, since it was rated slim. Consequently, it should be considered that plain black was more effective than the striped samples. Among the striped samples, g3 stripe of 10mm thickness hwas

7 rated slim, g1 stripe of 3mm thickness h, g2 stripe of 3mm thickness hand g2 stripe of 15mm thickness hwere rated thick, proving that increasing the number of stripes made legs appear slimmer regardless of the thickness of the stripes. Therefore it should be considered that the number of stripes affected the slimness-impression. The plain black was rated short and slim, being incompatible with the results in which the plain white was rated short and thick. The samples of g1 white stripe of 3mm thickness h, g2 white stripe of 3mm thickness h, g2 white stripe of 15mm thickness h and g1 white stripe of 25mm thickness h were rated rather long and thick compared with the plain black, which suggestively agrees well with the popular theory of striped patterns in which vertical stripes sportswear designs with partial arrangements of stripes, and to identify what type of stripe-designs for sportswear, among the variations of the thickness and number of stripes, would make legs appear long and slim. 1) The plain white was perceptually short and thick while all the black-lined samples with white backgrounds were perceptually long and slim, proving that a geometrical illusion effect will be obtained by arranging black lines on a white background. 2)It was found that increasing both the thickness and the number of stripes made legs appear longer on both white and black backgrounds. 3) It was found that increasing the thickness of a stripe made legs appear slimmer with regard to the slimness-impression from a show things longer and slimmer. Judging white background. from these results, it is conceivable that stripes on the Plain samples drove the impression to glong hand expansive white color of the stripes drove the impression to g thick hin conjunction with the popular theory of striped patterns and phenomena of color appearance in which bright colors such as white look large. The sample rated long and slim was g3 stripe of 10mm thickness h. This suggests that the thickness and number of white stripe on a black background were well in balance, making legs appear long and slim. On the other hand, the sample rated short and thick was g1 stripe of 3mm thickness h. This suggests that the stripe-effect against 4) It was found that the black background itself had an effect of compacting the appearance even without stripes on it. 5) Among the samples with white backgrounds, g2 stripe of 6mm thickness h, g3 stripe of 10mm thickness hand g1 stripe of 25mm thickness hwere recognized to make legs appear long and slim while Plain and g 1 stripe of 3mm thickness hwere recognized to make legs appear short and thick. 6) Among the samples with black backgrounds, g3 stripe of 10mm thickness h was recognized to make legs appear long and slim while g1 stripe of 3mm thickness h was recognized to make legs appear short and thick. the thickness of background of an extremely narrow stripe did not work effectively. 5. Conclusions We conducted the study to examine how human visual perceptions of the length and thickness of legs would be affected by References 1) G.Sai, K.Miura and H.Sasaki; The illusory effect of stripe patterns in clothing, Journal of Japan Society of Environmental Research for Fashion,Vol. 7-4, 44-47(1998) 2) M.Kobayashi, A.Masue, S.Nakagawa and

8 H.Imaoka; Effect of Striped Patterns of Clothing on Visual Evaluation of Physical Type, Journal of Home Economics of Japan, Vol.44, (1993) 3) H.Takamori; Apparent Lengths and Impressions in One-piece Dresses with Vertical or Lateral Pencil-striped Patterns, Journal of Home Economics of Japan, Vol.45, 47-53(1994) 4) S.Imai; A way of looking at horizontally stripes and horizontal wide, Psychology, 12 (1982) 5) JUSE Press Ltd.; SENSORY EVALUA- TION HANDBOOK, Edited by Research Committee of Sensory Evaluation, Union of Japanese Scientists and Engineers Copyr ight(c), (1973)