The first order of business was to deacidify the paper. Though it is in fairly good condition, the cotton rag paper is starting to yellow. We need to prevent it from becoming more brittle. This little spray bottle to the left has a formula that works wonders (see Preservation Technologies' website) and no worries! It won't harm the paper. Spray a fine mist on it, about 6-12 inches away, let it dry, and flip it over to repeat.
Once the letter was nice and dry, it's time to encapsulate it in polyester film (or Mylar for those of you who prefer that term). There is no adhesive involved. The edges are sealed with our ultrasonic welder and it melts them to seal it. We decided to seal it on all four sides to keep it from air, dust, etc. The air has been forced out from in-between the layers of film using weights before welding the edges. This also keeps a suction seal inside and the pieces cannot slide around (right now, it's one sheet of paper but there is a small tear in the middle). You can see in this picture that it is lying between the sheets of polyester film and the weight is lying on top of it. This final flap will be folded over, leaving only a small edge of polyester film to be welded shut.
Ta da! All four sides are sealed and it's time to trim the edges. You can see a close-up of the sealed corners here on the left, particularly if you click on the picture. Usually, we seal both of the longer sides first and then finish up with the shorter sides (if we are completely enclosing it). If the item was extremely large and couldn't fit into the welder, we may resort to using archival double-sided tape to seal the film. Luckily, this letter was a nice and easy size. Because this letter is exceedingly rare and valuable, I don't want to risk trimming the edges on our large guillotine-style cutter. (I must find you a picture of it). Instead, I trimmed the edges very carefully with scissors. I left a little bit of room on the inside bordering the letter just in case we need to open it up again. If necessary, we can re-use the same pieces of polyester film and weld them shut again.
I then had to decide if I wanted to put it back in its archival folder or do something special for it. All that had been requested was to deacidify and encapsulate it, but I couldn't just rehouse it in its sad little folder. I didn't have time to create a custom cloth portfolio, so instead a created a very thin tux box, custom fit to the letter. No glue is needed, just folding, creasing (with a bone folder of course!), and adding some double-sided tape to keep the two pieces together. When it's all finished, you have a four-flap enclosure that opens up to reveal the letter in the middle.
But this still wasn't good enough, I thought. The 20 pt board of the enclosure is a good step toward protecting the letter, but it's not stiff enough. Solution: Secure the tux box inside a pamphlet binder using thick strips of double-sided tape. PVA could work also, but then I'd have to sandpaper the pam bind to get a rough surface, let it dry, etc. Double-sided tape is quicker and isn't touching the letter, so I'm happy. I chose one that is a perfect size for our tux box and leaves a little space around it. It's a little dark in the picture, but you can see that it is secured inside the binder. All done! I feel a bit better that it's in nice, protective set of coverings. And we scanned it of course. This is the 21st century after all.
Apologies if any of the layouts of this post come across as wonky on your browser. I switched to the new editing software that Blogger has and though it's supposed to be easier, it really wasn't. Especially with putting in pictures and getting the text not to look too weird.