When sourcing sisal fabric, the quality is primarily determined by the fiber length, color purity, and weaving density. High-grade sisal should be creamy white to yellowish without dark streaks, indicating proper decortication and drying. For industrial applications like polishing wheels, ensure a high tensile strength and oil absorption capacity. For home decor or carpets, verify the GSM (Grams per Square Meter); a higher GSM typically indicates better durability and a tighter weave. Always request a UV resistance rating if the fabric is intended for outdoor use or areas with high sunlight exposure.