Cleaning of old paper

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.Noord Hollandse chais 2 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 togDirt behind the backing board.ether 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.

Aqueous cleaning

Aqueous cleaning, acidic buildup is leaving the artwork.

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.



Tear mending and repairing of paper

Repairing of tears in antique paper artworks.

Repairing even the smallest pieces and chips of paper is very important in the effort to conserve a piece of art.  The tiny missing chips or tears can cause even bigger problems in the future. Tearing starts to occur when the fibers of the paper are bent, folded or damaged in any other way. Mold activity will decrease the structural binding of the paper fibers. Acidic mattes, tapes, cardboard backings will also cause problems in the paper. Because of all these influences, the paper will eventually become brittle. When the piece is handled, tearing can occur, especially near to the edges of the paper. So mend this if you can. When done right, the mending of the tear will be almost invisible to the untrained eye.


So we strife for a nice clean sharp cut edge to prevent further tearing of the artwork at the fragile parts of the work on paper.

Obviously big tears need to be repaired, the work looks much better when the tear is mended and also, it prevents an even wider tear in the future. For the mending process I use a wheat starch based, home made glue, called Shinnori, which is a fresh wheat starch glue. The glue is free from harmful chemicals that can damage the artwork in the future and can be very easily removed if necessary. Next to the glue I use Kozo Mulberry paper of different thickness to mend the tear with. First step in the gluing process is preparing the glue, (Shinnori) itself.  There are many theories on how to prepare the Japanese wheat starch glue.  Some prefer cooking the mixture for up to an hour, some take twenty minutes of actual cooking the glue paste.  I tend to keep preparation time somewhere in the middle. Twenty to forty five minutes usually gets a good consistency.  I also store my lump of glue in the fridge in a clean container with a lid on it. You don’t want any microorganisms feasting on your wheat starch paste. After a week you’d better throw it away, just to be sure, not to introduce invisible mold spores onto the piece of art. A very good recipe can be found here. After I have glueingprepared the lumpy glue, I store it in the fridge. And when i’m ready to use it,  I’ll strain it through a very fine sieve and mix it with distilled water until a good consistency is obtained.

The Kozo paper comes in many thicknesses. Pick the thickness that is the closest to the paper you are about to mend. Don’t cut the Kozo paper in strips, but tear the strips of Kozo in a shape that matches the tear you are working on as close as possible.


As mentioned before, the glue is used for mending tears. Also, some artwork that is in very poor overall condition with a lacking structural integrity, can be glued,repairing and mending or mounted if you will, on a piece of Kozo paper ,again with the help from the Shinnori glue. You will have to make sure that it is as finely structured as possible. Just mix the Shinnori glue paste with demineralized water, and with a sieve make this mixture as fine as possible.







Jo Hulstein