A Pantone guide is a physical reference, and physical things age. A faded guide is worse than no guide — because you'll trust it anyway.
Why guides fade
Ink and paper react to light, air and handling. Over time colours shift, yellow and dull — slowly enough that you may not notice until a job comes back wrong.
Pantone recommends replacing guides roughly every 12–18 months for colour-critical work.
Signs it's time
Look for yellowing paper, dull or marked swatches, dog-eared pages and fingerprints on the chips. Compare a suspect guide against a new one and the drift is often obvious.
If your guide has lived in sunlight or been heavily thumbed, treat it as suspect regardless of age.
How to make yours last
Store guides closed and out of direct sunlight, handle chips by the edges, and keep a "master" guide for approvals separate from the one that travels. When in doubt, replace it — a new guide costs far less than a reprint.
