Sizing is the most critical factor in this category. You must verify if the supplier uses US, EU, or Asian sizing standards, as these vary significantly. Request a detailed size chart including bust, waist, hip, and thigh measurements for every style. Ensure the supplier implements a tolerance range of no more than ±1-2cm. It is highly recommended to order physical samples across the full size range (e.g., 1XL to 5XL) to test the 'grade' or scaling of the patterns, ensuring the fit remains ergonomic as sizes increase.