Visual discrimination of hygiene tissue softness in the absence of haptic feedback

Abstract

Our perception of the softness of materials is dominated by the subjective interpretation of haptic stimuli — touch. Although softness is defined by the way a material deforms when force is applied, other sensorial inputs, such as vision and hearing, can be used to complement haptic feedback or when the material cannot be touched. Surface and bulk softness elements of hygiene tissue, such as surface roughness, embossing pattern, and bulk can be assessed visually. Softness is reported as the number one desired quality of hygiene tissue. So, it is of paramount importance to understand the criteria a consumer uses to judge softness visually. Consumers must rely on these other non-tactile senses at point-of-purchase or in e-commerce because they cannot interact with a product to judge the softness. This study proposes that a consumer can accurately gauge softness by sight alone, and that factors such as color tone, embossing, and image quality all affect the perception of softness. Stiffness and mechanical properties of the sheet cannot be observed by eye and can contribute to errors in visual judgement. We conducted an experiment using a complete pair ratio (round-robin) type comparison to evaluate the perceived softness of altered images of hygiene tissue with unaltered images. Images of hygiene tissue were altered to represent different lighting conditions or product color and digital image degradation. Our results suggest that yellow hygiene tissue is perceived as less soft than blue, and un-embossed tissue as less soft that embossed tissue. Reducing the image resolution to 10% of the original did not negatively affect the perception of softness.