Books survive a century in the right room and three monsoons in the wrong one.
What actually destroys them
Humidity, which foxes paper, warps boards and starts mould at the top edge first.
Light, which fades spines. A shelf facing a window sorts your collection by colour over a decade.
Insects, which do real and rapid damage to paper in a damp cupboard.
Pressure and poor shelving. Books packed too tight damage their own spines; books leaning unsupported warp.
What to do instead
- Upright, supported, not leaning, and not jammed so tight they have to be pulled by the headcap
- Oversized books flat, never on their fore-edge
- Off the floor and not against an outside wall
- Out of direct sun
- Air circulating — a sealed glass cabinet in a humid city is worse than an open shelf
Dust jackets
Where a jacket carries the value, a clear archival cover protects it from handling and light. It is cheap and it is the single best thing you can do for a modern first edition.
Discs
Upright in their cases, out of heat. Disc rot is real and humidity and heat accelerate it. A disc stored flat in a hot stack is the one that stops playing.
What it costs
Shelving in the right place, which is free, and jacket covers for the few books that deserve them.
Questions people ask
Is a glass-fronted cabinet good?
Only with some airflow. Sealed and humid is how mould starts.
Can I store books in a loft or basement?
No to both — heat swings above, damp below.
What about silverfish?
Keep the area dry and clean; damp is what invites them.