When sourcing heavyweight hoodies, the most critical factor is the fabric weight, which should typically range between 350 GSM to 500 GSM (grams per square meter). Ensure the material composition is either 100% premium cotton or a high-cotton blend (e.g., 80/20 cotton-polyester) to balance breathability with structural integrity. Look for double-needle stitching at the seams and cross-grain cutting to prevent vertical shrinkage. Additionally, verify the use of high-density fleece or French Terry lining for superior warmth and hand-feel.