When evaluating epoxy powder, you must prioritize Particle Size Distribution (PSD), as it directly affects the smoothness and thickness of the coating; typically, a range of 30-50 microns is standard for electrostatic spraying. Additionally, verify the Curing Schedule (temperature vs. time), ensuring it aligns with your facility's oven capabilities to prevent under-curing (brittleness) or over-curing (discoloration). For functional applications, check the Glass Transition Temperature (Tg) to ensure the coating remains stable under your specific operating environment.