The aim of this study was to investigate the effect of some cellulose polymers mixed in a semipermanent dyestuff on the dye uptake of yak hair fiber and color fading after repeated washing cycles. Two different classes of commercial polymers were tested: non-ionic and cationic. Formulations based on a mixture of HC and basic dyes, with different molecular sizes, were employed as representative dyestuffs. UV-Vis spectroscopy and colorimetric measurements were used to analyze the extracted dyes from the yak hair cuticle and cortex. The results obtained indicate that the presence of cationic polymers in the dye bath improves both the quality of the dyeing process and the antifading effect during the first washing cycles.

Our external appearance plays a key role in everyday life's social interactions. Hence, taking care of our appearance allows us to adjust and protect ourselves, as well as communicate emotional disposition (i.e. sympathy or aversion) and social information (i.e. values, status). However, some discrete body parts or characteristics appear to be more salient than others in contributing to global body image. For example, authors showed that facial attractiveness is one of the best predictors of overall physical attractiveness and represent one of the primary factors influencing global self-esteem. Make-up is therefore ought to play a major influence in these parameters. Moreover, in a previous study whose subject was to explain the reasons that motivate women to make-up, we showed a high implication of specific psychological traits in correlation with two make-up functions (i.e. psycho-behavioural profiles 'Seduction' and 'Camouflage'; group S and group C, respectively). The purpose of this study was to assess the possible relation between our two psycho-behavioural profiles and some morphological parameters know to be involved in facial attraction (i.e. facial asymmetry and skin visual quality). First of all, our study revealed for women from the group C a greater asymmetry of the lower face (i.e. mouth area) that could be related to a possible larger amount of negative emotional experiences. Concerning make-up behaviour, women from the group S more extensively manipulated their relative facial attractiveness, by using a large range of colours, but also through a significantly longer make-up process used to adjust their visual asymmetry and therefore increase their potential of attractiveness. On the overall, our results suggest that make-up is used differentially, according to stable psychological profiles of women, to manipulate specific visual/morphological facial features involved in attractiveness.