Process efficiency and water conservation are critical components of sustainable textile dyeing. Innovations in these areas aim to optimize resource usage, minimize waste, and reduce the overall environmental footprint of the dyeing process. This section reviews four key advancements: low liquor ratio dyeing, waterless dyeing technologies, closed-loop systems, and advanced oxidation processes. Low liquor ratio dyeing is an approach designed to minimize the amount of water used in the dyeing process. By using a lower volume of water relative to the weight of the fabric, this method significantly reduces water consumption and the amount of dye and chemicals required. Studies have shown that low liquor ratio dyeing can reduce water usage by up to 50% compared to traditional methods . Furthermore, this method provides better dye deagglomeration compared to the traditional methods (Figure ). However, achieving consistent color quality can be challenging with reduced water volumes . Waterless dyeing technologies, such as supercritical CO2 dyeing and air-dye technology, have been developed to eliminate the need for water in the dyeing process entirely. These technologies use alternative mediums, such as carbon dioxide or air, to apply dyes to textiles. Supercritical CO2 dyeing, for instance, uses CO2 in its supercritical state to dissolve dyes and penetrate textile fibers, offering a water-free and energy-efficient dyeing method . Air-dye technology employs air to transfer dyes onto fabrics, significantly reducing water and chemical use . While these methods offer substantial environmental benefits, high initial investment costs and the need for specialized equipment can limit their widespread adoption .