When evaluating wool fabric, the most critical factor is the fiber fineness, measured in microns; a lower micron count (e.g., Super 100s to Super 150s) indicates a softer, more premium hand-feel. Additionally, check the fabric weight (GSM) to ensure it suits the intended use—150-250 GSM for lightweight summer suits and 300-500 GSM for heavy overcoats. You must also verify the composition percentage, ensuring it is either 100% Virgin Wool or a specific blend (like wool-cashmere or wool-polyester) that meets your durability and cost requirements.