Analysis of thermochromic label elements and colour transitions using sensory acceptability and eye tracking techniques

This study utilized eye tracking and sensory techniques to evaluate the acceptability of different thermochromic label elements that exhibited colour transitions. Participants (N = 40) evaluated a baby-formula label (baseline) with two trial versions of the same label using colour transitions [Tr1 = colour change in brand name and primary-figure (koala); Tr2 = colour change in secondary-figure (snowflake)]. Labels appeared on a computer-screen (virtual) for 10 s and participants assessed liking of label elements [areas of interest (AOI)] using a 9-point hedonic-scale. Participants also evaluated printed labels (physical). Complete fixation times (CFT) and number of fixations (NOF) from AOIs (brand name “Baby Grow”, koala, product-description, snowflake, weight) were assessed. Results showed that figures had higher liking scores compared to brand name (6.47-6.88 vs. 5.76). For eye tracking measurements, the koala had the highest CFT (1622-1689 ms) and NOF (3.4-3.5) for all transitions. Liking of brand (Odd-ratio = 1.7-2.0; Tr1/Tr2) affected preference. The preference of virtual and physical labels did not differ. When colour transition was applied, fixation duration was affected, with gaze being drawn to transition elements. Eye tracking was useful for measuring reactions towards labels with changing colours. A combination of sensory data and eye tracking helped to understand preferences.