Selecting a factory requires evaluating production capacity, material safety, and customization capabilities. Prioritize manufacturers that use high-quality ABS plastic, which ensures flexibility and prevents whitening when bent. Verify that the factory holds ISO 9001 certification for quality management and MSDS (Material Safety Data Sheet) for the adhesives and pigments used. For B2B buyers, it is essential to confirm if the factory offers OEM/ODM services, including custom mold opening and private label packaging, to ensure brand differentiation.