This chapter examines how ethnicity, sustainability, and craftsmanship converge in the contemporary fashion industry, using Hong Kong-based brand Loom Loop as a focused case study. Grounded in an insider qualitative methodology, the research explores mud silk production, cultural storytelling, and artisan collaboration to illuminate how a heritage-driven label can achieve both ecological responsibility and economic viability. Building on Elkington’s (1997) Triple Bottom Line and the proposed 3P+C framework, this study demonstrates that cultural sustainability functions alongside social, environmental, and economic pillars, offering a more holistic lens for evaluating ethical fashion practices. The analysis reveals that integrating cultural identity with slow fashion principles appeals to ethically conscious consumers, fostering stronger brand loyalty and market differentiation. However, operational challenges—such as sourcing skilled artisans, balancing premium positioning with production scalability, and avoiding cultural commodification—underscore the delicate balance required to sustain heritage-based models. Despite these hurdles, Loom Loop’s experience indicates that intangible heritage can significantly enhance both a brand’s ethical credibility and its commercial appeal, particularly when artisanship is conducted transparently and respectfully. Through a case-based perspective, the chapter advances academic discussions on how ethnic traditions, environmental stewardship, and artisanal skills can mutually reinforce each other. In doing so, it enriches debates surrounding fair labour, green materials, and cultural authenticity, suggesting that heritage-driven approaches are neither peripheral nor incompatible with modern fashion markets. By offering insights for designers, policymakers, and scholars, the chapter ultimately calls for wider recognition of cultural heritage as a core pillar of truly sustainable and innovative fashion.