Preserving a Letter with an Official Seal

Dear Donia,
How should I preserve a letter with an official seal?

How to Do Your Own Matting and Hinging


Q. Dear Donia,

I have a very special letter with the White House seal that I want  preserve. I thought about encasing it in wood. What would be the best methods to save this item for my family? Thank you, Emmalou
A. Dear Emmalou,

Encasing your letter in wood would not be the best thing as wood off-gasses and those chemicals can be very damaging to paper.  Ideally, you would frame and display this item properly.

When it comes to framing your letter, be sure to look for a framer who will use archival mat board and techniques. You shouldn't have too much trouble finding someone in the Raleigh/Durham/Chapel Hill areas. 
The best mat board to look for is what we call museum rag board. It comes in many shades of "white" and you should have not trouble finding one to complement your letter. Whether your are going to a framer or you are doing the matting and framing yourself, please take a look at the helpful leaflet from the Northeast Document Conservation Center on "How to Do Your Own Matting and Hinging." This guide will let you know how to properly mount the letter to the mat board (hint, not tape!) so it will be safe for generations to come. As for the glazing, you will want to look for glass that has UV blocking properties like TruVue glass.
Finally, when framing, it is best to pad the rabbet of the frame with an inert foam such as Volara to better seal the glass to the wood frame and block out pollutants from the air, especially if you have a fireplace that you use.
When on display, ideally the letter would be on an interior wall that is not in direct sunlight.
All of these steps will help preserve the letter for your family.
I hope this helps.