Conservation: Take II

Remember my last post about conservation? Here’s some of her advice in action:

1. While cataloging Michelle and I came upon a fur coat in the museum’s collection. The accession record noted that the donor said that the coat was made of beaver fur. After examining the coat, with white gloves of course, we were unsure if it was actually made of beaver. To be honest, it felt like a poor quality carpet. With Caroline’s help we pulled a tiny piece of the fur from a less obtrusive part of the coat and took it over to the microscope. Although I probably should have already learned this is my biology 100 class, apparently you can differentiate fur by its structure. By looking at our “beaver” fur under the microscope we saw that the fibers were woven together in a knit-structure – a sure sign that it is not a real fur. Caroline also taught us about leather. Cow hides can be split into several layers and each layer can be used for many purposes. By putting several different leather gloves under the scope we could see which was the top grain and which were lower down. Ever heard of “top grain” leather being the finest and most expensive? That’s where that comes from.

2. In the afternoon Caroline held an impromptu “workshop” for us interns and several of the museum faculty. She taught us all about document conservation. One important thing to know when dealing with paper is that paper is hydrophilic – it likes water. Have you ever spilled something on your carpet and when it dried it left a “tideline” of dirt along the edge of its path? Me too! Caroline taught us how to life those stains – particularly when they appear on paper. These tidelines need a place for the dirt to go. What you do is wet the stain and put a blotter paper (such as Volera) on top and leave it for a while to set. The capillary action will draw out the stain as it moves from the wet to the dry environment.

Caroline also taught us how to seal a tear on a historical document. To practice we each took a dollar bill with both a clean cut and a rough tear in it. The “glue” that we used was made from wheat paste that she made at home. It looks like a clear silly putty. To seal the cut you take a paint brush and apply a generous amount of the wheat paste along the cut lines on both sides. Then you make a sandwich. First put down a piece of glass, a piece of blotter paper, Volera (it kind of looks like tissue paper), the document or in our case $$, Volera, blotter, glass and then a weight on top – remembering that all conservation must be symmetrical.

An hour later you pull the paper out from its layers. The tears should already be pretty hard to find at this point. To stabilize the cut you next apply Japanese tissue paper. This is thin and expensive paper that is made of durable, strong fibers but when used it blends in into the document. You next apply a small amount of water – always use tap NOT distilled water as tap has ions in it – to the Japanese paper and place the tissue paper to the back of the document. 10 hours later your tear disappears!

These techniques were very fun to learn and helped to remind me that although many artifacts come into museums and are not in “display” condition it does not mean that all hope is lost! With some simple conservation techniques stains and dirt can be lifted, fabrics can be reshaped and documents can be pieced back together again. Neat, huh?

See you next time.

Allison