Te Papa has a broad range of collections, so works on paper can include watercolours, prints, drawings, pastels, photographs, documents, maps, wallpapers, playing cards, fans - even cardboard election polling booths!
Before deciding what conservation treatment will be best, the conservator needs to understand the item itself. What is it made of? How was it made? What is its significance? What is its aesthetic, historical, and spiritual purpose ? Each collection item is unique, so the conservator tailors the treatment to the individual item’s needs.
A major cause of deterioration in paper is acidity. It produces overall darkening, brittleness, and foxing (the appearance of small brown stains), which can be seriously disfiguring, particularly in artworks. In time, acidity can weaken paper so severely it crumbles. Acidity can come from within the materials used to create the item itself, or it can be caused by contact with acidic materials.
Slowing the rate of deterioration is vital for long-term preservation, particularly in collections made from poor paper. Keeping paper items away from sources of damage and contamination is a key focus. For example, artworks on paper are supported by acid-free folders and mats, and protected within acid-free storage boxes or permanent frames.
Light not only causes fading, but also creates a chemical reaction which weakens the paper itself. Light exposure is monitored at Te Papa, and paper items on exhibition are changed regularly to limit light damage and ensure future generations also have a chance to appreciate them.
For many items already affected by poor matting and framing or past display conditions, the key challenge for the paper conservator is to try and stabilise the deterioration. Treatment of works on paper will usually also involve cleaning and consolidation, structural repairs, and aesthetic reintegration.