When evaluating bonded fabrics, you must focus on the bonding strength (peel strength) to ensure the layers do not delaminate after washing or use. Key metrics include GSM (Grams per Square Meter) for weight consistency, breathability ratings (MVP - Moisture Vapor Permeability) for functional textiles, and waterproof ratings (hydrostatic head) if the fabric is intended for outdoor or performance wear. Ensure the adhesive type (e.g., TPU film, PUR hot melt, or flame bonding) aligns with your final product's durability requirements.