When evaluating volleyballs for B2B procurement, focus on the construction method, material quality, and bladder type. Professional indoor volleyballs should feature microfiber synthetic leather for a soft touch and moisture management, while outdoor/beach versions require water-resistant composite materials. Ensure the ball uses a butyl bladder for superior air retention and is laminated or thermally bonded rather than hand-stitched to maintain a perfect spherical shape and aerodynamic stability.