Understanding the hierarchy of hair quality is essential for B2B buyers. Virgin Hair is the highest quality, as it is chemically unprocessed and harvested from a single donor with intact cuticles running in the same direction (Remi/Remy). This prevents tangling and ensures a lifespan of 1-2 years. Non-Remy hair is often collected from multiple sources, leading to cuticle misalignment which causes matting unless treated with an acid bath and silicone coating, which reduces durability. Buyers should also verify the 'Ratio' (e.g., Double Drawn vs. Single Drawn); Double Drawn hair contains a higher percentage of full-length strands, providing thickness from root to tip, whereas Single Drawn is thinner at the ends.