When evaluating Cotton Silk (often called Mashru or Cotton-Silk blend), the blend ratio is the most critical factor; a common high-quality ratio is 70% cotton and 30% silk, providing both breathability and sheen. You must verify the thread count (TPI), where a higher count (e.g., above 300) indicates a denser, more luxurious feel. Additionally, check the fabric weight (GSM)—lightweight varieties (60-80 GSM) are ideal for scarves, while heavier weights (100-150 GSM) are better for garments like shirts or dresses.