When sourcing Pokemon cards, authenticity is the highest priority. Ensure the supplier provides high-resolution scans of both the front and back. Look for crisp printing, correct font types, and the distinct 'blue core' layer in the card stock. For holographic cards, verify the texture patterns and light refraction; counterfeit cards often have a flat, vertical-only shine. Always request third-party grading (PSA, BGS, or CGC) for high-value individual cards or factory-sealed cases with the official Pokemon Company shrink-wrap for bulk inventory.