Surface finish and touch—a case study in a new human factors tribology

This paper is concerned with the sliding contact of a finger tip over rough glass surfaces. It reports measurements of how the roughness affects a person’s feelings caused by the sliding when the person believes the glass to be intended to be used for cosmetics’ packaging. The main purpose has been to gain experience in design of surface touch experiments, self-report data collection and multi-variate statistical analysis of that data, to link subjective outcomes with their physical cause. The paper contains details of these activities. Tests have been carried out with glass surfaces both acid etched and grit blasted, to attain a range of surface roughnesses (Ra) from approximately 1–10 μm. The main conclusion about the feelings caused by sliding is that while a surface is less rough than a finger tip, it generates desirable feelings but when it is rougher than a finger tip it generates undesirable ones (all in the context of what is deemed to be desirable for cosmetics’ packaging).