This comprehensive B2B sourcing guide analyzes how global intimate apparel brands, private labels, and e-commerce sellers can navigate the seamless underwear manufacturing landscape in China for 2026. The article breaks down the structural differences between vertically integrated OEM/ODM factories and trading company layers regarding machinery ownership, real MOQs, production lead times, and itemized pricing transparency. It provides actionable insights into technical verification across Santoni circular knitting, laser cutting, and TPU bonding technologies, while teaching buyers how to mitigate overseas supply chain risks using parallel multi-item tech packs and official database credential checks (OEKO-TEX, BSCI, GRS, ISO 9001)