The core of a high-quality neck pillow is its filling. For the premium B2B market, High-Density Memory Foam (50D or above) is the industry standard due to its slow-rebound properties and ergonomic support. For the budget-conscious or travel retail sector, Food-grade EPS Microbeads offer lightweight portability. Ensure the outer cover is made of breathable, hypoallergenic fabrics like magnetic therapy cloth, bamboo fiber, or cooling silk, and verify that the foam meets CertiPUR-US or OEKO-TEX Standard 100 to guarantee it is free from harmful chemicals.