A small but vital team support the safe storage of National Museums Liverpool's vast collection of more than 4 million objects. As well as making objects accessible, our goal is to ensure the safety and preservation of collections in the stores.
Throughout an object's lifetime it will continue to naturally deteriorate. Our storage management team work to ensure that the rate at which objects deteriorate is as low as possible to secure their survival for future generations to enjoy.
This involves working closely with curators, conservators and our estates department to maintain the best possible environment and storage conditions for our collections including 'good housekeeping', controlling environmental conditions, pest control, using appropriate packaging materials and choosing the right types of physical storage systems such as racking and shelving.
Choosing museum storage materials
Conservators select storage materials to ensure that they do not contribute to the deterioration of our objects. Only conservation grade, pH neutral materials are used to pack and protect objects such as Plastazote cushioning, bubble-wrap, plastic pallets, crates and boxes and coated metal shelving.
We use these inert materials to prevent pollutants from causing a chemical reaction and further object deterioration, for example acids which are secreted form certain woods will cause corrosion of metals.
Just as we ensure that our display cases are able to bear the load of objects, we also consider the load bearing of our storage shelves and put systems in place to accommodate different collections and also to manage the space that we have as efficiently as possible. For instance our marble sculptures will require more heavy-duty racking than our paper archives or ethnographic basketry.
The type of storage needed also depends upon the objects themselves. Small items in boxes can easily be placed straight onto shelves whereas paintings, rolled textile or hanging costume will require different styles of storage support.
Dust and dirt harbour unpleasant things such as fragments of human skin, and can be excellent food for microbiological activity. Dirt can also disfigure and scratch the surface of objects. The store management team is tackling the removal of surface dust and dirt which has accumulated over many years within certain storage areas and implementing improvement in packaging and general storage conditions.
Most recently we completed a project to remove dust and mould from objects affected in store. The level of organic dust had provided an ideal food source for mould spores to feed on once the humidity reached a certain level allowing them to grow, or 'bloom'. Mould is a danger to collections, in a similar way to woodworm and carpet beetle, and we have to monitor carefully for any outbreaks.
The environment and pest control
Within museum storage it is important to recognize that the collections need a more stable environment than people, therefore offices, meeting facilities, and other areas are kept separate where possible. Objects like a cold stable environment, which means the continued and close monitoring of temperature and humidity levels by our environmental officer.
On gallery the temperatures are kept higher for visitor comfort but will remain at a constant level. In store we are able to drop the temperature to a more suitable level. The most important thing is that the conditions are kept constant. because fluctuations in temperature and the amount of moisture held in the air can cause objects to expand and contract causing damage such as warping, splitting, flaking or corrosion depending on the material type.
Working closely with our estates management team we ensure that our buildings are watertight to prevent sources of harmful water vapour and to reduce dust and pest access. All store management staff are able recognise the signs of a pest infestation such as furniture beetle (woodworm), carpet beetle, moth or mould. Further information on pest management at National Museums Liverpool can be found under conservation science.