Self-storage is on the rise, still! It has been for years. Britain has the largest self-storage industry throughout Europe. Some people use it for short-term storage solutions, others use them for the long haul. Some sites are multi-complex buildings with staff, others are self-storage containers, which are essentially reconditioned shipping containers transformed into storage units located on secure sites, usually within industrial estates.
Whatever the reason you may consider using them, there are conditions that need to be met to safely store your artwork to prevent it from incurring damage. Both in transit to and from the unit and for the duration that your artwork is in storage.
The type of storage matters
With such a large industry, it should come as no surprise that you have options to consider. It is not a case of showing up, agreeing on a price and terms, then moving your belongings in. You have choices. One of those choices is climate-controlled storage facilities. You need that for artwork.
Temperature and humidity are what you ultimately need to be controlled. For artwork preservation, room temperature is ideal. The average room temperature in the UK is around 20oC. Artwork fairs best when it is kept at temperatures cooler than 23oC. For paintings, you need to be careful of the cold too. If temperatures take a sudden chill, it can cause the paint film to become brittle, resulting in damage. To avoid high fluctuations, aim to have a climate-controlled storage area with temperatures maintained between 16oC and 23oC.
Humidity for artwork
Ideal humidity levels are 40% to 50% for art in storage. That being said, it does depend on the age of the work. Antiquity art that has been around for decades, perhaps over a century, will have withstood loads of changing conditions. Modern artwork made with the likes of acrylic paints is unlikely to be as capable of withstanding sudden changes that antique works can withstand.
As a guideline, 40% to 50% relative humidity is safe for art, but the highest risk factor is sudden fluctuations. Any more than a 5% change to humidity or temperature within 24 hours can be damaging. That is where a climate-controlled environment is beneficial for storing your art.
Packing artwork for container storage
Packaging is part of the preparation process that will be needed before your artwork goes into storage. A common practice to protect frames from dust is to wrap them in plastic film. The risk to that method is that it can trap humidity, increasing the risk of mould and fungal growth.
Art that is framed needs to be sealed. Unframed art can be protected by sandwiching the piece between two pieces of acid-free mount board. The thicker the better.
Where to store your art
The higher the better. The floor is not where you want to have your framed art sitting in storage. Especially if you are using an outdoor self-storage container. At ground level, there is a risk of water or even just vapour from condensation puddling, that will damage your belongings.
Framed art should be stored by leaning the frames upright against the wall and with a breathable fabric cloth placed over it giving it some heat protection from overnight temperature drops.
For unframed art, placing them at the highest point in the storage unit, and with hardboard placed between prints prevents accidental damage from heavier items that could fall on top of them.