How stamp grading works: the 70–100 scale explained
What the numbers mean, the named tiers from Fine to Gem, what graders actually look at, and why a single point can move a stamp's value.
Read the guide ›Stamp grading guides
Plain-English explainers on how stamps are graded, what drives a grade, and how to decide what's worth submitting — written to go alongside the PreGrader.
Is your stamp worth grading? How to decide before you pay
Grading costs money and time. Here's how to weigh the fee against the value a high grade adds — and how a pre-grade helps you decide before you submit.
Read the guide ›Stamp centering explained: why it drives the grade
Centering is the single biggest visible factor in most grades. What "well centered" means, how it's measured, and how much it's worth.
Read the guide ›