Judith Bannerman, Zane Cunningham, Mark Underhill and Amanda Heath: Micro-fade testing and anoxic framing of manuscript documents frm 1782-1859: Results of a research project.

Micro-fading is a new technique which can be applied to various historical artifacts made of almost any material and in conjunction with anoxic framing, it can determine the possible fade rate of manuscript inks over time and the ideal environment in which to slow the degradation process down. A specific object was chosen for the current research, in this case two iron gall ink on paper documents, one from 1782 and one from 1859 were chosen for their common occurrence in archives around the world, age of the objects and narrow range of materials used in their construction.

As many of the manuscript artifacts are fragile, micro-fading has an advantage over many traditional methods of analysis as it can be done in situ with each flourish of the pen having the potential for several data sets to be collected without causing damage to the overall object. In addition, micro-fade testers have the capability to test the fade rate of an object through glass, enabling an object to be placed into a specific environment and monitored for any degradation over time.

The micro-fade tester is a machine that can perform accelerated light-aging testes, rapidly, non-destructively and can be used directly on the artefact. The light intensities and colour spectrum of the reflected light between 400-700nm is then measured and compared to the Blue Wool standard scale #1, #2, #3 and #4. The data gathered is related to L*a*b* and Delta E* in order to generate fade rates.

Once the level of fade for each object is determined the data can be used in the Light Damage Calculator developed by the Canadian Conservation Institute to determine, under specific lighting conditions, what would happen to the various colours over time. The CCI Light Damage Calculator is based on the original slide rule light damage determination which is widely used in many fields.

The documents are then put into various sealed environments using the new Anoxic frame developed at Tate Britain in order to observe how varying the oxygen and relative humidity levels within the chamber could slow the degradation process. The conditions used included approximately 0%, 5% and 21% oxygen at 50% RH and 40% RH.

The results from the current study indicate that many of the iron gall inks are fugitive between a Blue Wool #1 and a Blue Wool #3, and therefore any changes in display should be done with the most fugitive colours in mind. However when placed under anoxic conditions the inks appeared to stabilize to a Blue Wool #3-#4, indicating that by not only cutting the light that is falling onto the manuscript but also reducing the amount of oxygen that it is exposed to, the life of the object when on display can be extended.

Micro-fading in conjunction with Anoxic framing, is a new tool for conservators to accurately create display regimes, light level limits, display limits based on the damage created in 100 years and in reduced oxygen environments, dark rotation schedules for museums and to preserve historical objects for the future. With further study micro-fading and Anoxic framing can contribute to our knowledge of how objects fade and how to preserve them for the future.