What to monitor
Start with the variables that actually explain the risk.
For this material group, the environmental record is most useful when it captures the things below and keeps them tied to the object, space or display context.
- Relative humidity and short term change
- Temperature and rapid heating or cooling
- Visible light and cumulative lux hours
- UV where relevant to the display
- Pollution and storage materials as a separate collections care issue
What can go wrong
The number only matters because of the damage mechanism behind it.
Moisture movement
Paper fibres absorb and release moisture. Repeated change can lead to cockling, distortion and stress, especially where media, mounts or bindings react differently.
Light
Light can fade inks and pigments and weaken paper. The damage builds up, which is why time on display matters as much as the spot lux reading.
Heat and chemistry
Higher temperatures can speed chemical deterioration. Modern acidic papers, newsprint and some unstable media can age much faster than good rag paper.
Published guidance
Useful examples, with the caveat kept attached.
Museums Galleries Scotland’s paper guide gives 45–65% RH, 10–20°C, a maximum display level of 50 lux and no more than 100,000 lux hours a year as practical examples for general paper collections. It also recommends keeping short term RH changes small. The National Archives takes a repository view and says traditional archives should be stored between 13°C and 23°C, with an average below 18°C, while noting that film and photographic archives can need specialist storage.
Where judgement comes in
Those figures are not interchangeable rules. Parchment, stretched paper, watercolours, iron gall ink, photographs and composite bindings can all need a more specific assessment. The object’s condition, previous environment and how it is mounted matter too.
How this maps to LÆFAN
Keep the reason for the profile with the readings.
Give the store, gallery or case its own profile rather than treating every paper object the same.
Track RH and temperature continuously where useful, and keep light exposure as lux plus lux hours when objects are displayed.
Record the source and effective date of the profile so a future report shows why those limits were chosen.
Use Campaigns for temporary exhibitions so a display period does not get mixed into the long term storage record.
LÆFAN does not decide the conservation limit for you. It records the profile your institution has chosen, the source or rationale behind it, where it applies and what happened while it was in force.
Sources & further reading
Where the examples on this page came from.
Caring for paper collections
Open source ↗Removing the risks to archives
Open source ↗Conservation and lighting
Open source ↗Environmental management for collections and climate sustainability
Open source ↗Sources checked 6 October 2026. Guidance and standards can change, so follow the linked publisher page before adopting a value into policy.