Tanning agents are generally categorized into Chrome (Mineral), Vegetable, and Synthetic (Chrome-free) agents. Chrome tanning agents (Basic Chromium Sulfate) are preferred for high-speed production and creating soft, flexible leathers like those used in garments. Vegetable tanning agents (Tannins from bark/wood) are ideal for heavy-duty leathers, belts, and eco-friendly luxury goods, offering a firm structure and natural patina. Synthetic agents (Syntans) are often used as retanning agents to improve specific properties like lightfastness, fullness, and dye uniformity.