Why is temperature also strictly controlled in museums?

Temperature drives the relative humidity. By maintaining a strict 68°F (20°C), museums prevent the relative humidity from swinging, which causes organic materials to constantly expand and contract.

What is the worst thing for archival storage?

Rapid fluctuations. It is actually better to have a slightly high, but stable humidity, than an environment that rapidly swings between dry and damp daily.

Ideal Relative Humidity for Libraries & Museums

What happens if humidity is too high?

When relative humidity stays above 60%, paper absorbs moisture and becomes soft, inviting 'foxing' (brown spots) and rampant mold growth that can destroy rare books and canvas paintings.

What happens if humidity is too low?

If the air drops below 30% RH, paper, leather bindings, and parchment dry out and become brittle, increasing the risk of tearing and cracking when handled.

Frequently Asked Questions

Why is temperature also strictly controlled in museums?: Temperature drives the relative humidity. By maintaining a strict 68°F (20°C), museums prevent the relative humidity from swinging, which causes organic materials to constantly expand and contract.
What is the worst thing for archival storage?: Rapid fluctuations. It is actually better to have a slightly high, but stable humidity, than an environment that rapidly swings between dry and damp daily.