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It seems like a strange process to intentionally get paper wet—reading in the bathtub is something of an extreme sport fraught with danger. However, when performed carefully, the result can be quite beneficial for some collections.
These pages are from the book Istoria de fenomeni del tremoto, an Italian volume published in 1784 containing dozens of intaglio prints about earthquakes and their destruction. Many of the pages have stains over the images and they have all accumulated the levels of dirt expected from centuries of existence. It was determined that the prints would be truer to their original artistic intent and original appearance if the stains could be reduced and the paper brightened overall. It was time for them to receive a much-awaited bath, known as “washing” in conservation terms.
Washing is a procedure that uses water to remove degradation products that have accumulated in the paper over time. It’s an irreversible treatment, altering a page’s acidity, flexibility, appearance, and dimensions. Because it’s irreversible, a great deal of planning and preparation is especially necessary beforehand to avoid any unwanted surprises.
Before reaching this washing stage, surface dirt was carefully removed with cosmetic sponges. If this dry-cleaning step isn’t performed, washing the paper can actually end up permanently embedding the surface dirt deep into the paper fibers. Imagine paper fibers expanding and loosening up in a bath, reaching out to grab surface dirt, only to pull the dirt back closer to the body when the paper dries and contracts again.
After dry-cleaning, the paper was also closely examined under a light table for any trace materials that might bleed or bloom in water, such as flakes of rust. This process also helps illuminate the papermaking process itself. This paper wasn’t the highest of quality for its time as evidenced by the variety of speckling and mottling across the print. Spots can indicate bunches of paper fibers, dirt, stray bits of ink, or even metal fragments.
For washing, pages are sandwiched between sheets of polyester fabric. Western-style paper is extremely fragile when wet, and the polyester sheets enable the paper to be handled indirectly. The sheets can be easily removed from the paper.
Before washing, the paper is layered between sheets of dampened blotter paper. This helps gently introduce moisture into the paper so that the submersion into the tray of water isn’t as much of a shock.
The pages are then placed in trays of water. Alkaline deionized water helps draw out acidic contaminants in the paper that have built up over the years. It a process that is not unlike a gentler version of adding borax to your laundry wash—a pH buffer strengthens water’s innate ability to clean. This acid-base reaction also helps neutralize the pH of the paper. Each page is left to soak in a tray for about 20 minutes and then is transferred to another tray of clean alkaline deionized water for an additional 20 minutes. Finally, the pages are carefully removed and left to dry flat on a drying rack for about 24 hours.
For these pages, washing has noticeably reduced staining as well as lightened the paper overall. The paper also feels more flexible and has more dimension—the impression left behind from the printing press has become more pronounced. The pages likely now look a bit more like how they might have appeared 250 years ago.
Header Image: Book pages soaking in carefully calibrated trays of water.