When sourcing slip agents, primarily Amides (like Erucamide or Oleamide), you must evaluate the purity level (typically >98%) and the melting point, as these dictate the migration speed to the polymer surface. For high-temperature processing, Erucamide is preferred due to its lower volatility and better thermal stability compared to Oleamide. Additionally, check the particle size (beads vs. powder) to ensure compatibility with your feeding system and to prevent clumping during the masterbatch production process.