Monday, June 23, 2014

Relaxing and Rehumidifying an Old Document - Part 1

Back in July 2013, Denise Levenick, over at her blog, The Family Curator, wrote about flattening photos and documents that had been rolled up.

Since I have quite a few of those myself, I decided to give her instructions a try. You really should read her post. She does an excellent job of explaining the background and providing instructions. Head over and read it, then come back. I'll be waiting.

OK so now that you have a better understanding of what Denise did, here are my results.

First, I selected a smaller document that spent several decades being rolled up so it wasn't about to flatten out on its own.

Into the "humidification chamber" it went.

After about 8 hours, I was able to unroll it. I was surprised at how much the humidity changes the feel and flexibility of the paper.

After about another 10 hours I pulled the document from the chamber and placed it on the blotting paper.

Another layer of blogging paper was placed over the document. Then a bunch of the biggest, heaviest books I own were placed on top. I left town for a couple of weeks and forgot all about it.

Here's what it looked like upon my return. Pretty slick eh?

Note: The 8 hours and 10 hours is just how long I happened to leave the document in the humidification chamber. Maybe it could have been done in a shorter amount of time, maybe not. I also wonder how much the humidity in the surrounding environment affects this process. Here in Arizona, our humidity is pretty low. Sometimes it's almost non-existent. Seriously. It was 7% recently outside. Inside the house the humidity approached 20%. So maybe rehumidification takes longer? I don't know.

Next I tried an over sized document that had been rolled up much longer. This one proved to be more of a challenge. Check back tomorrow to see how that went.

Other posts in this series: 

Relaxing and Rehumidifying an Old Document - Part 2
Relaxing and Rehumidifying Photographs - Part 3
Relaxing and Rehumidifying an Old Poster - Part 4 

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© 2014, copyright Michelle Goodrum


  1. Michelle,

    Thanks for re-posting Denise's blog post. I'd like to point out that her post was specific to old PHOTOGRAPHS. These photographs were created by fluid reacting to the emulsion layer; they can respond positively to being retreated with water.

    Conservation of paper materials is, as most conservation, all about chemistry. Humidification of documents is a very different task for this reason and, while as your end result shows it works, the process can take significantly longer. And, if not properly tested, humidification can destroy a document.

    There were some important things left out of Denise's instructions: The water should be deionized or distilled; chemicals in ordinary tap water can have a long term, detrimental effect on materials as they attach themselves to the molecular structure of the paper. Also, typically following the humidification process for documents, the materials should be flattened (see the link below)

    I know this seems 'nit picky', but conservation should be about 'do no harm'. I would hate to see someone try this on a document without water soluble ink, only to find what they were trying to straighten is no longer legible. As an Archivist I worked with a Professional Conservator to conserve an 1851 letter that had become unreadable due to improper storage. It took almost 6 months in a humidification chamber to become flat. The process depends on the composition of the paper (1830 paper is totally different than 1930 paper) and, as noted above, the type of inks used need to be taken into consideration.

    I applaud you for using this method to straighten your documents. You can find more information about the conservation of documents at The Northeast Document Conservation Center. Their website at nedcc (dot) org and select the 'Preservation Leaflets' button.


    1. Thanks for your informed observations, Laura. You bring up some important points so I'm going to refer to them in the posts for the rest of this series.

      The document in this particular post was from the 1950s. You bring up critical issues regarding the age of papers and the types of inks used. Also, I hadn't given any thought to using deionized or distilled water. Our tap water here in Arizona is loaded with minerals so distilled water would have been a much better choice.

      Thanks again for your comments and referal to the Northeast Document conservation Center. I hope you read the rest of the series without cringing too much ;-) It's a warts and all description of my experiences. Good and not so good. But then that's how we learn from each other isn't it?