Don't Let the Pigeon Play with Tape

There is a fabulous children's book called "Don't Let the Pigeon Stay Up Late" about a tired little pigeon that doesn't want to go to bed.  It is part of a series of books about all sorts of things you shouldn't let the Pigeon do, and after last Thursday, I want to add a new title to the series: "Don't Let the Pigeon Play with Tape".

The Special Collections Library recently acquired the archive of a bank from a small town in southern Virginia.  The staff at the bank had carefully saved many documents from the bank's founding and from important events throughout the bank's history.  This is just the sort of news that makes archivists very happy.  What the staff also did was frame a number of the documents and put them on display.

This is just the sort of news that makes archivists and conservators anxious, because where there are window mats and framed documents, there is often tape.  (Insert dramatic, horror-movie scream here.)

 
In a better world, the framer would have used some sort of photo corner to hold the document in place instead of taping it to the top of the window in the window mat.  Perhaps the roll of tape said "archival" on the package.  Who knows the tape may even be pH neutral, but that does not mean that directly applying tape to an artifact is ever a good idea.  With pressure sensitive tapes (the kind you pull off a roll and smush into place with your fingers) the adhesive doesn't really cure but rather becomes tangled in the fibers of the paper and that is what is holding everything together.  So removing the tape means you are trying to untangle the adhesive from the glue without tearing the surface of the paper.

This was the scariest piece since not only did I have to get the tap off the top of the document, but there were two additional sections of tape toward the bottom of the document.  It was nerve wracking work, but we were very, very, lucky.  After two hours and some very fine work with my casselli spatula I was able to liberate all of the documents from their window mats. 

So even though we had a happy ending, I would still say Don't Let the Pigeon Play with Tape!!

More Tape Progress

Another week, another Randolph letter, and yet another type of tape.  Again, I started my testing protocol, but this time, I decided to take a picture of the tape residue with my cell phone, and keep the image handy while I tested.

I often track my progress by stopping the application of solvent and lifting the piece to check for residue on the chromatography paper.  The process can be a little clumsy if you have a large piece of paper (although in this case I don't), but what can be really tricky is noticing progress, especially if the adhesive residue doesn't stain the chromatography paper.  I find myself wondering "is this acetone doing anything?"

But having this "before" picture right next to the actual piece I can look back and forth and and notice very quickly even minimal change in the adhesive residue on the letter.  Very cool.

Tape Progress!

As a book conservator, I spend almost as much time thinking about tape as I do thinking about books and paper.  Tape (or pressure-sensitive adhesive as we call it in the biz) is one of the easiest ways to mend a tear, and is a standard supply at home or at the office. 

But tape doesn't age very well.

Take a look at this before treatment (BT) photo of a letter from John Randolph of Roanoke.  A previous owner "fixed" the holes and tears in the letter with pieces of tape.  The shiny section at the top left is tape carrier (the layer of plastic that holds or carries the adhesive) that is on this (recto) side of the letter.  The dark square in the lower right of the letter is tape that is on the other (verso) side and the discoloration is a result of the adhesive in the tape sinking sinking through the paper. 

Here's the letter from the verso side, see the shiny surface of the tape carrier in the lower left corner and the translucent section in the top right.  This is a great example of highly enmeshed and cross-linked adhesive and brittle, distorted carrier!

Removing the carrier is relatively easy, but removing the adhesive from the paper can be very tricky.  Generally conservators use solvents, first testing with water and then on to stronger solvents like ethyl acetate or acetone.  If a straight solvent doesn't work, then testing begins again with a mixture.  It can take a while to find the right solvent, or right combination but if you don't find it, the adhesive won't budge; its not as though solvent  X will get it to move a little and solvent Y will move it faster. 

In this case, straight solvents didn't work and after I tried a few mixtures that didn't work, I reached out to my colleagues in other labs.  Everyone was generous with their recipes and eventually I found a mixture that fit the bill.  This is another verso shot of the letter taken just after I completed the treatment.  Note how the discoloration is gone, as though the tape had never been there in the first place.  Pretty amazing!

Sometimes even after all the meticulous work of testing and applying tiny patches of solvent with a cotton swab, conservation feels like magic!