ars longa

lining application (UVA WWI posters)

this poster was particularly brittle. we began by giving it a bath (instead of dry cleaning), then applied a lining (instead of doing countless mends on all of the holes). as you may have noticed, i spent quite a long time removing linings previously, and now i'm putting one on. the linings i removed were very dramatic and used material that could continue to degrade and hurt the poster. the lining i applied to this poster is very gentle - japanese tissue (light) and wheat starch paste (easy to remove), unlike the cotton fabric (heavy, tasty for bugs) with heat set tissue (a pain to remove).

drying between two thick pieces of felt

bath - between 2 layers of reemay

1) position poster on a large sheet of mylar, wet down. take care to make sure there are no wrinkles and all of the pieces line in properly, as the paper will continue to expand as it gets wet. for this poster it was a bit tricky due to the many pieces that had been torn or were completely detached..

2) position a sheet of japanese tissue (weight depends on the paper) on another oversize sheet of mylar, coat with a layer of thinned wheat starch paste (about the consistency of whipping cream) starting from the center and fanning out. make sure to get out any wrinkles or bubbles that appear

3) apply paste to the poster, again working out from the center and removing wrinkles and bubbles. a soft brush works alright for this, but a roller works particularly well to get out wrinkles

4) pick up the mylar+tissue (it helps to have another set of hands) and carefully lay it on top of the poster+mylar, making sure that the whole poster is covered by the tissue and there are no large air bubbles. work out any small air bubbles with a bone folder, although be careful near areas that are detached because they will sometimes move as paste is pushed out

5) remove the top layer of mylar, then cover the mylar+poster+tissue with reemay and blotters, put weight on top (plexi and bricks) and let it sit to dry for a little while (we waited about half an hour)

6) take off weights and blotters and replace with gortex (fabric coated with plastic that allows water vapor to pass through but not liquid water, neat stuff, fragile, expensive), let dry!

adhesive removal: heat set tissue (UVA WWI posters)

one poster had some burned cotton that was a bit harder to remove

two of the UVA posters had linings on the back consisting of a cotton fabric attached by a heat set tissue made of adhesive and a thin paper carrier. the fabric came off easily, but the tissue was much more difficult. initially i tried removing it just through mechanical means (sliding a microspatula or scalpel between the tissue and the poster). in some areas it came up easily, but others were better adhered. for these areas i used the hot air pencil to soften the adhesive so the microspatula could slide under the tissue and raise it up to be removed. this worked well, although not all heat set adhesives would've responded in the same way.

half of the cotton lining removed

start of tissue removal

...still working on the tissue

adhesive removal: scotch tape (UVA WWI posters)

scotch tape is a pressure sensitive adhesive on a plastic carrier. it can be removed by using a hot air pencil (developed for the computer industry to make computer chips) to soften the adhesive

the evil scotch tape

the magic tools: hot air pencil and micro spatula

1) removal - you can't see the hot air pencil
pointing at the microspat. it's there. it's helping.

2) plastic carrier removed! adhesive... still there

3) vinyl eraser to the rescue again

everything off! the paper is still discolored,
but that's the price of scotch tape.

adhesive removal: masking tape (UVA WWI posters)

masking tape is a pressure sensitive adhesive on a paper carrier. this masking tape was old enough that the carrier lifted off easily, but the adhesive had hardened to the paper. to remove it, acetone is used. we began with an acetone chamber (acetone soaked blotters) but we could tell it was too aggressive. it softened the adhesive so it could be removed, but it also began to soak through the paper. we switched to removing it with an acetone soaked cotton swab, and were successful.

acetone soaked blotter, making a solvent chamber

adhesive starts to soften

removal of adhesive using a cotton swab!
(sometimes soaked with additional acetone)

adhesive removal: glassine (UVA WWI posters)

glassine tape is a water soluble adhesive on a paper carrier. it comes off easily with methyl cellulose - a derivative of the plant fiber cellulose that, when mixed with water, creates a gel. it allows moisture to be applied in a controlled way without completely saturating the paper.

glassine tape removal with methylcellulose

paper tape removal (again, water soluble adhesive on a paper carrier, just thicker than the glassine paper carrier):

tear mending: filling (UVA WWI posters)

when something has a large loss, the same process as mending a tear is used. however, this leaves japanese tissue visible on the face of the object (here: posters). if the loss is in a margin or a large white space this isn't a problem, but in the case that the loss is in a colored or dark area of the poster it stands out quite a bit. to keep the mend from being a distraction, it can be filled. all this means is that the area is toned, here using colored pencils. this way it's still visible as a loss (the texture difference alone would make it obvious), but it doesn't distract the viewer from the rest of the image.