When choosing archival records to add to a display case or exhibit space a decision must be made whether to display the original or a copy. Sometimes it is necessary to display the original because the item holds such high historic significance and making it publicly accessible is important, for example, exhibiting the Canadian Constitution. If you are considering displaying an item that could fade first determine if displaying the original is necessary or if a copy of the item would suffice.
What media and material fades or discolours more quickly when exposed to light?
- Iron gall ink
- Analine dye
- Water-based inks
- Coloured photographs
- Cyanotypes and blueprints
- Wood pulp based paper
This is not a comprehensive list, and there may be other media and materials that will fade quickly upon light exposure.
It is also important to consider the auxiliary features of the records, such as fabric ties, paper seals, and stamps; all may fade when exposed to light.
How can you minimize exposure to light if the original must be displayed and has light sensitive media or materials?
Ensure there is UV filtering film on windows and UV filtering light tubes on lights that emit UV. Ensure that the light does not exceed 75 lux. It is recommended to place curtains over windows to assist with controlling lux. Other items should not be placed in front of or partially over light susceptible items due to uneven fading caused by the shade, leaving unsightly fade marks.
It is recommended to change out exhibit material every three months so that original records are not overexposed to light.
While it is recommended to display high resolution coloured copies when possible of archival records susceptible to fading, if the item holds little to no historic significance there may not be a risk of losing important information even if the item does fade. The archives staff preparing the display should consider all options and determine if the return is greater than the risk.