Cleaning of paper
Paper art Hygiene, dry cleaning
Dry cleaning is the dry removal of dirt and micro-organisms from the artwork with the help of dry sponges, brushes and granulated rubbing gum. Bigger particles, like insect specks and rust spots, can be scraped away with a sharp tool. At my workshop I use dry cleaning in two ways: with a clean brush and granulated gum, going over the entire artwork in a circular motion and the other way is by scraping away superficial spots with a knife and then vacuuming the residue so it gets removed right away. A large part of the dust and micro-organism particles are removed this way, leaving a cleaner and more freshly looking artwork.
In the process of conserving and restoring art, dry cleaning is an important step because over time, the dirt and dust particles will get embedded deeper into the fiber of the paper, where these particles merge with the paper over time, causing staining, yellowing and browning and creating a fertile breading ground for microorganisms. In time, the paper will become brittle and eventually dissolve all together because of these microorganisms. The traces of the fungi’ s waste product can actually be seen under a microscope in the form of strings running through the paper. Next to the cleaning of the paper, the frame and glass must be cleaned thoroughly, preferable killing all the microorganisms so nothing gets transferred back to the sanitized paper. Dry cleaning is also an important step before aqueous cleaning of the work. Most of the bigger dirt particles are removed before the paper is submerged in a bath. We don’t want spores and dirt being released in the bath where they can contaminate the whole paper!
If possible, use a new piece of glass. If you want to reuse the old one make sure all the microorganisms are killed. I would recommend using bleach to kill microorganisms, preferably wearing gloves to make sure no fingerprints are transferred onto the paper. The frame should also be cleaned with light soap and water. After the paper is dry cleaned it can be framed again. If necessary the artwork can be soaked in liquid to remove acidic build up.
This is used when the paper is in good overall shape but suffers from foxing or extreme yellowing. Acidic buildup in the paper caused by pollution, (people used to smoke a lot) or backing on acidic cardboard and acidic matting. Also acid in the used inks and in the artworks own paper can cause foxing and yellowing. Sometimes, tape used to matte the artwork also causes ugly yellow stripes where the glue is merged with the paper. This glue residue feels slippery when the artwork is wet. If possible, remove this sticky layer, rubbing gently, when the paper is in the bath.
To preserve the artwork, aqueous cleaning can improve the artwork and preserve it for future generations. Acidic buildup will rinse out of the paper where it will soak for some time in distilled water with added calcium-hydroxide. A test on the inks is done to make sure it can handle liquid cleaning. Usually different colors and inks will react differently when coming in touch with water so these are tested with a q-tip and water + water and ethanol before taking the plunge. When its clear the colors won’t start to run, the artwork is placed on a piece of spun polyester, where I usually spray the artwork with a ethanol/water solution. This is to protect the fibers of the paper. The water/ethanol solution penetrates the fibers much faster then ordinary water or distilled water, so the shock as is lessened. The shrinking and expanding of the fibers goes much faster causing less damage. Wetting old and antique paper is always demanding on the paper. However, if you want to preserve the art piece as best as you can, its often wise to do so. Most of the time the process of foxing comes to a halt.