When evaluating PP bags, focus on the GSM (Grams per Square Meter), which determines the fabric thickness and strength; typically, 70-100 GSM is standard for heavy-duty industrial use. Ensure the denier count (yarn thickness) aligns with your load requirements. For bags intended for outdoor storage, verify the addition of UV stabilizers to prevent degradation from sunlight. Additionally, check the weaving density (e.g., 10x10 or 12x12 tapes per inch) to ensure the bag can contain fine powders without leakage.