Buyers should prioritize fabric weight, typically measured in ounces (oz). For standard jackets, 12oz to 14oz denim is ideal for durability, while 8oz to 10oz is better for lightweight, seasonal items. Ensure the material composition is clearly defined, such as 100% cotton for authentic vintage feel or cotton-spandex blends (2-3% elastane) for stretch comfort. Additionally, verify the wash technique (e.g., stone wash, acid wash, or enzyme wash) as this affects both the aesthetic and the fabric's structural integrity.