History Nebraska Blog

Treating Certificates at the Gerald Ford Conservation Center

Last month we looked at two certificates in the Nebraska History Museum that had been previously treated by other conservators.  Despite the fact that the certificates were the exact same age, they had been treated differently and therefore had aged in different ways.

BT Certificate 5

Before treatment photos of the two certificates. 

BT Certificate 2

Although they are the same age, both of the certificates were treated in different ways at different times in the past.

In order to treat these certificates, paper conservator Hilary LeFevere and technicians Vonnda Shaw and Megan Griffiths reduced any surface soiling on the front and the back of each certificate. 

Upon closer examination, it was found that the certificate on the left was structurally very stable and well adhered to the heavy-weight lining paper. Although it was over-cleaned and bleached at the time, it did not require additional treatment such as washing, as was initially proposed. For this reason, it was also decided not to remove the lining.

Washing the Certificate

The certificate in its first water bath.  You can see the water turning yellow as the acidic byproducts wash out, compared with the clean water on the right.

For the other certificate, the lining was carefully removed and the inks were tested for solubility.  During lining and adhesive removal, the certificate split into sections along the creases where the certificate had been folded in the past. This was expected and is common with brittle, previously folded documents.  Once it was determined safe to proceed, the certificate was washed in a series of baths to reduce the degradation products in the paper.

Spot Washing on Suction Table

The certificate was immediately dried partially on the suction table and spot cleaned with a brush to further draw out discoloration.

A final rinse in alkaline water, was done to impart a buffer into the paper to counteract acids. After washing, the certificate was immediately lined on to Japanese paper for structural support.  Once dry, paper losses in the margins and along fold lines in the certificate were repaired using Japanese paper toned with fluid acrylic paint.

Lining the Certificate

Each section was carefully lined onto a thin sheet of Japanese tissue, making sure to align all the edges.

Both certificates were then housed in clear, Mylar sleeves so they can be safely viewed and handled and they will be stored in an acid-free, lignin-free folder for their long-term care.  They are both more stable now and with proper storage and handling will be for many years to come.

BT Certificate 2

A side-by-side comparison of the certificate before (left) and after (right) treatment. 

AT Certificate 1

You can see that the paper is lighter and the losses have been filled.

BT Certificate 5

A side-by-side comparison of the certificate before (left) and after (right) treatment. 

AT Certificate 3

The surface is cleaners and the hinges on the back have been removed.

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