A card is thin, stiff and entirely ruined by one bend. The packing for it is well settled and worth following exactly.
The order
- Soft sleeve first, so nothing touches the surface
- Rigid holder — a toploader or a semi-rigid card saver
- Tape the top of the holder, so the card cannot slide out, with the tape on the holder and never on the card
- Team bag or a small plastic bag around the holder, against damp
- Between two stiff boards, taped as one block
- Into a rigid mailer or a small box — never a plain envelope
Six steps, a minute, and it is the difference between a sale and a dispute.
Graded cards
A slab is strong against bending and weak against impact at the corners. Bubble wrap it, then box it with the voids filled. A slab that arrives cracked is a damaged item even if the card inside is untouched.
Heat and damp
The slow killer in this category. Cards left in a hot room curve; cards left in a humid one stick inside sleeves and spot. Store flat, out of the sun, away from an outside wall, and do not leave a parcel sitting in a vehicle. Monsoon and your stock.
Lots
Bundle in rows between boards so nothing can shift, then box. A loose pile of cards in a padded envelope will arrive with rounded corners and it will be nobody's fault but the packing.
Questions people ask
Can I post a single card in an envelope?
Not safely. The rigid mailer is the point, and the cost difference is small.
Should I tape the toploader shut?
Tape the top so the card cannot slide out, with the tape on the plastic only. Never tape the card, the sleeve, or across the opening in a way that forces a buyer to cut near it.
Is bubble wrap enough for a slab?
Bubble plus a box. Bubble alone still lets a corner take the whole impact.