Gray scale image analysis was applied for the measurement of visual features of plain knitted fabrics with 5 kinds of stitch densities. Mean of the gray level for the digital image, the angular second moment, correlation, contrast and entropy which were extracted from the gray level co-occurrence matrix, and the fractal dimension were measured as visual feature parameters. The fractal dimension was determined from the fractal analysis of the relief of the curved surface of the gray level image. Complexity, contrast, stripe or linearity, uniformity, roughness, fineness, flexibility, light sensation and beauty of plain knitted fabrics were evaluated by sensory evaluation according to the rating scale method. The visual feature parameters and the sensory evaluation values for plain knitted fabrics were found to depend on the stitch density. Beauty of plain knitted fabrics was discussed from the viewpoint of orderliness and complexity according to the principle of beauty proposed by Birkhoff.

  The mechanism of coloration, tensile strength, bending resistance and waterproof of the fabrics dyed with persimmon tannin juice were investigated through colorimetry, spectroscopic method, tensile testing, canti-lever testing and spray testing. The test cloths woven of cotton, flax, silk, rayon, nylon and polyester were irradiated ultraviolet rays or heated after dipping into persimmon tannin juice. All of the test pieces were dyed with persimmon tannin juice and the greater the water absorption property of the fiber was, the deeper the test cloth was dyed. The cloths dyed under irradiating ultraviolet rays showed thinner color, higher reddish color and more yellowish color than the ones heated. It was inferred that such coloration of dyeing with persimmon tannin juice resulted from the change of the characters of the pigments and tannin of persimmon due to ultraviolet rays and heat. The tensile strength, bending resistance and waterproof property of the cotton cloth dyed with persimmon tannin juice were stronger, harder and greater than the ones before dyeing. It was considered that the tensile strength, bending resistance and waterproof of the fabrics dyed with persimmon tannin juice depended on the film of slightly soluble phlobaphene formed from tannin of persimmon. investigated