MITRA Forum Question Details

Hi Marko -  the environmental situation you're describing is a problem many museums, historic houses, and galleries face.  Conservators and other collections care professionals have been struggling with this and, generally speaking, we've come to the conclusion that the parameters can be set a little bit wider than we originally thought.  Although having strict parameters in place is ideal for some materials (such as certain photographic materials) it's actually more sustainable and more important that there are fewer drastic fluctuations in temperature and relative humidity.

If you are concerned with the low relative humidity in your apartment when the building's heat is on (something I struggle with in my own apartment, too) you can get a humidifier fairly cheaply.  When you use it, make sure that it's not directly next to any of your paintings or drawings as they can become wet, but placed in the same room can help to bring the relative humidity up a little bit.

Sorry, I meant to add current, general guidelines for works of art on paper are around 59-77°F and a relative humidity between 45-55% (+/- 5%).  For most works on paper it's better to minimize extreme fluctuation than it is to stay within narrowly defined parameters.  Let me know if you have any other questions!

At very low humidity, the paper substrate can contract as it loses moisture, which can result in tension between the paper and the media (particularly with heavy applications of media).  Also, some media can become more friable (powdery).  It's certainly not ideal, but the biggest risk occurs if there are dramatic fluctuations in relative humidity, causing an object to expand and contract rapidly and resulting in physical weakness.  I wanted to ask what instrument you're using to read the relative humidity?

If you do get a humidifier, I would first test it in a room where you don't have any art to make sure that it works without spraying or misting and that it doesn't raise the humidity too rapidly.  I would also only use a household dehumidifier in a large room; in a small space, it may be too much.  An old trick that people used to use in a dry space is to leave a pan (or pans) of water out, which can raise the humidity slightly.  Of course, you have to be careful not to put a pan of water anywhere it can spill and damage your work, and the water would need to be changed regularly.  It probably is also only suitable for a smaller space, but you could try it out and see if it makes any difference at all (it may not).

To answer your big question, which is how artworks have survived for hundreds of years in various environmental states…there are a lot of different ways to approach this question.  My personal opinion is that materials tend to remain stable when there are fewer fluctuations, even if the temperature and relative humidity aren't ideal.  There are a lot of other factors that affect the longevity of an item, including pH, light, frequency of use, luck, etc.  I also think that when we're looking at artifacts or art made long ago, we are often looking at it in its changed form.  Conservators and collections care staff impose stricter environmental parameters on items because we are trying to keep them as unchanged as possible while they are under our care…but we are aware that this is a nearly impossible task, and that nothing lasts forever.  I don't think any conservator would want you to feel afraid to experiment with your work; it's our jobs to let you know what might happen to the materials you use, but in no way do we want to hinder creativity.

​Framing works on paper under glass does create a micro-climate, which has the effect of slowing fluctuations in temperature and relative humidity within the frame and creating a more stable environment.  That is something to consider.  Overall, I wouldn't worry too much about the low humidity in winter - you clearly care a lot about your art and take good care of it, and as I said it's worse for objects to go through extreme fluctuations than it is to be in fairly steady periods of low humidity.

We are always happy to answer any questions you might have!

I share this only because I found the history of how modern humidity and temperature recommendations came about. For example, this paragraph details how the storage of museum paintings in underground slate quarries in Wales during WWII, which happened to also provide unusually stable environments, really marks the birth of the whole field of how the environment impacts paintings:

"With the outbreak of the Second World War, mixed collections from the British Museum and the Victoria and Albert museum were removed to quarry storage at 60%RH, 60°F and survived the war in very good condition.[[24]: p.2] The National Gallery's collections were evacuated to storage in the Manod slate quarry, Wales.[[25]] Conditions in the slate caves were a constant 47°F and 95 to 100%RH; brick shelters were built in the caves to house the paintings [[26]] and 'simple heating' was used to control the climate in the shelters to 58%RH, 63°F/17°C with 'exceedingly minor variations.'[21: p.194] Prior to the removal to Manod, a technician had been employed eight months out of every year to deal with cracking and blistering in the panel paintings; during the first year of storage in Wales (1941- 1942), his work reduced to one month and by 1945 he had nothing to do; after the War ended, the paintings were returned to the essentially uncontrolled environment of the National Gallery, and an epidemic of blistering, warping and cracking broke out.[21] This very positive experience of climate-controlled quarry storage contrasted powerfully with the experience of evacuating collections to bomb-proof storage in the tunnels of the London Underground (subway) system during the First World War, when uncontrolled damp had caused serious damage to collections.[[27]]"

The rest of the document can be found here:

Development of humidity recommendations in museums and moisture control in buildings

Enjoy.