Getting started
A graded card — a "slab" — is a card sealed in a tamper-evident case with an authenticated grade and a verifiable cert number. That authentication and locked condition make slabs more liquid and usually more valuable than raw cards. Start in a category you follow, buy fewer better cards, and decide which raw cards are even worth grading.
Understanding grades
Grades run 1–10 (10 is Gem Mint) and are judged on centering, corners, edges, and surface — and the company on the slab (PSA, BGS, SGC, CGC, TAG) affects both perception and price. The jump from a 9 to a 10 can multiply value, which is why a card’s grade is part of its identity.
Valuing your collection
A card is worth what comparable copies actually sell for — realized comps, not asking prices, at the exact grade. Population reports explain scarcity; sales volume tells you how much to trust a number. Slabline values every slab from real comps across eBay, Heritage, Goldin, and PWCC.
Protecting and insuring
Your cards face risks a stock never does — theft, fire, environmental damage — and your homeowners policy almost certainly will not cover them at full value. Store slabs cool, dry, dark, and secure, and document a broker-ready insurance schedule kept current as the market moves.
One number for the whole collection
The Slabline Score brings it together: a credit-style 0–1000 index of how well-protected your collection is across insurance, concentration, storage, liquidity, and provenance. Scan a few slabs and Slabline values them, scores the collection, and builds the insurance schedule — free for up to 25 cards.