Background: The global fashion industry faces mounting pressure to adopt sustainable practices; however, consumers continue to struggle with information asymmetry at the point of purchase. Eco-labels have emerged as a key mechanism for communicating environmental and ethical credentials, but their influence on how consumers evaluate product quality remains poorly understood. Despite over 450 eco-labels operating globally, it remains unclear whether their presence genuinely alters quality perceptions or merely signals ethical values without affecting purchase-related evaluations.

Purpose: This thesis examines how eco-label presence influences consumers' perceived quality of sustainable clothing. Specifically, it investigates whether eco-labels have a significant impact on four quality dimensions: material integrity, durability, longevity, and sensory comfort, and whether those changes in perception translate into purchase intention. The study addresses a gap in the literature by manipulating the eco-label cue and measuring its effect across multiple quality dimensions.

Method: This study adopted a between-subjects experimental survey design (N = 127). Participants were randomly assigned to either a treatment condition, in which a product image included official eco-labels, or a control condition, in which the image was identical but label-free. A split-sample reliability analysis first examined whether the eco-label influenced evaluative coherence across conditions. Independent samples t-tests then examined the effect of eco-label presence on each quality dimension (H1a–H1d) and on purchase intention (H3). Pearson correlation analysis tested the relationships between each quality dimension and both overall perceived quality (H2a–H2d) and purchase intention.

Conclusion: Eco-labels act as cognitive anchors that reorganise how consumers structure quality-related information, even when mean-level attribute scores do not change substantially. Of the four dimensions, only sensory comfort showed a statistically significant eco-label effect, consistent with Cue Utilization Theory: eco-labels add the most value on credence-based dimensions that consumers cannot assess through intrinsic cues alone. Longevity was the strongest predictor of both overall perceived quality and purchase intention, but the eco-label's direct effect on longevity perception was only marginal. This mismatch explains why eco-label exposure did not significantly increase purchase intention, confirming the persistence of the attitude-behaviour gap. Eco-label effectiveness is dimension-specific, and brands must pair eco-label presence with longevity-framed messaging to bridge the gap between improved quality perception and actual purchase behaviour.