Monday, October 31, 2016

Preservation 101: How Light and Humidity Impact Paper

We have been spending a lot of time on this Queen Elizabeth I document, and I bet you are wondering....if this manuscript is such a big deal, why is it squirreled away in some archival basement?

                                Excellent question!

The short answer...

This particular document is delicate and has some significant conservation needs. It is sensitive to light and handling (it did just celebrate its 440th birthday after all).

The longer answer

While this manuscript may be susceptible to exposure, we regularly utilize authentic collection items in our teaching and museum programs; Primary Source Seminar, Archival Ambassadors, Teacher Ranger Teacher, and our internship program to name several. And when we aren’t working with the “real deal,” we are bringing folks close to that experience through our digital and hands-on exhibits.


Decoding Shakespeare's Monarch quill and manuscript station, 
at Washington's Headquarters unit.

But while we’re on the topic of conservation needs, let’s take a look at what is going on with our 1576 Elizabeth I.

They say hindsight is 20/20 and that seems to be exceptionally true in the field of preservation. As new advances in preservation science come about, collections managers work hard to care for our most valuable historical treasures. We often shudder at the interventions earlier generations of historians made, prior to our contemporary understanding of the properties the of paper, ink, and adhesive acidity; the dangers of permanent stabilizing or alteration measures; and the inherent value of historical context and provenance.

Today we are going to explore how light and humidity impact paper, while also examining the particular preservation concerns of this 1576 manuscript.

A collections manager’s number one enemy: the environment !

We work hard to keep artifacts stable by minimizing the risks incurred from exposure to ultraviolet light and fluctuations in temperature and relative humidity. Read more about our field standards here.

When paper artifacts are exposed to spikes and dips in temperature and humidity over time, they are susceptible to warping, tearing, brittleness, creping, foxing, or mold blooms. Inks may flake, transfer, or erode paper. And certain dank climates provide the optimal environment for pests, like silverfish and boreing insects like moths and beetles (colloquially known as bookworms).


We have two primary lines of defense again environmental detriment.

                         1. Storage and Stabilization

                         2. Monitoring and Mitigation

One of the most important things any historian can do, amateur or professional, is to provide a safe home for their artifacts to rest.

                    Keep paper artifacts:
      • cool and dry
      • flat and supported
      • (interleaved) or separated
      • able to "breathe" as to avoid microclimating

data loggers, placed at 
various locations around 
the museum and storage 
areas read RH, temp, 
and light intensity.
At the museum, we use archival-grade acid-free folders, paper, and boxes, but those materials aren't always accessible for the home historian or small historical society. Many genealogy websites provide helpful tips of how you can improvise > CHECK THIS OUT. *

*Most modern computer or printer paper is low acidity and can work in a pinch if you need to create folders to interleave photos or isolate acidic materials.

At Morristown NHP, we conduct regular environmental monitoring inventories, watching for anomalies and mitigating risks by adjusting the conditions when necessary. Climate control, humidification regulation, and environmental monitoring are our best indications of what is going on in our storage spaces.   

Queen Elizabeth I ...440 Years Later

As you can see this manuscript has been glued to a piece of paper, a common nineteenth-century stabilization practice. The thinking here was that the scrapbook would keep the paper intact, flat, and with its label... and it does. It also puts the sheet directly in contact with adhesive and a bed of highly acidic card stock.

Modern preservation thinking insists that all measures be 100% reversible, so that in the event we come to realize better techniques, we haven't caused any permanent alteration to the chemistry or structure of the artifact.

click to enlarge

The gluing has caused the paper to lay imperfectly, creating folds and skewing the visible text. Not only does this present a conservation concern, it impedes the researcher.

A collector has written notes directly on the manuscript. Though we do not practice marking our manuscripts today, this was not an uncommon practice. In fact, early collectors were very interested in collecting signatures, and not necessarily intact manuscripts. Dealers would commonly circle or mark signatures as a person today might circle a job in a want ad. The signature, not the manuscript, was prized. Modern manuscripts are, on occasion, directly marked with artifact or catalog numbers, but it is generally done so with a reversible process. Luckily for us, the collector's marks here appear to be written in graphite and present little conservation concern. Will we have the markings removed? Nope. They are now historical and part of the document's history or provenance.

A closer look at the paper reveals some slight staining and an obvious attempted mend. As our transcription illuminated, the edge of the paper is torn and the text truncated. The tear has been mended with a fragment of machine made paper (as indicated by its lack of chain lines).

How do we store our Elizabeth I?

While I work hard to stabilize and preserve our paper artifacts, I am not a conservation scientist so my "intervention" will remain minimal. I have removed this manuscript from its scrapbook, but am unable to reverse the adhesive. The best thing I can do is minimize the chemicals from migrating any further by interleaving with sheets of acid free paper. Interleaving paper can be used to separate or isolate individual pages or act as a buffer between a manuscript and the page to which it has been affixed. 

I have also created more suitable housing for this manuscript. A layer of mylar sheeting, a custom acid free folder, and an acid free clam shell box. These layers of support provide protection from moisture, light, and environmental fluctuations, while allowing the artifact to "breathe." 

Works Consulted

"About Paper Conservation at NESCC." Northeast Document Conservation Center.

"Care, Handling, and Storage of Works on Paper." Library of Congress.

"The Environment." Northeast Document Conservation Center.,-relative-humidity,-light,-and-air-quality-basic-guidelines-for-preservation

"Foxing." Society of American Archivists.

Levenick, Denise May. "How to Organize Your Family History Archive." Family Tree Magazine.


  • The Cursive Learning Curve & Future Historians' Dilemma

No comments:

Post a Comment