Individual cards under $20 ware generally shipped in a penny sleeve in a top loader in a Ding Defend cardboard envelope. (This is the $1.32 option)

If the purchase price is over $20 it will generally ship USPS Ground Advantage, which is in a penny sleeve in a top loader with corrugated cardboard protection and the inside a bubble mailer. (This is generally about $5)

Bulk lots will ship in penny sleeves in paper sleeves with cardboard protection, in an envelope(s) depending on the size of the lot.