Cleaning and Washing
If the pages of a book are particularly dirty, they can be cleaned and washed in a water bath. The book must first be totally disbound. Each page is checked for excessive dirt and/or markings. These are cleaned off with a soft brush or an acrylic plastic eraser (which will not abrade the paper). Then each leaf is gently placed in the water and left to soak for 15 minutes to 1 hour. The water will usually turn “tea colored” as the acids and dirt in the paper is dissolved by the water. A second bath is used to rinse the paper before it is removed to the drying rack. The last step is to press the paper while it is just slightly damp to flatten it. Care must be taken on how much pressure is used so as not to flatten the impressions of the printing on the page.
The result is paper which is “brighter” looking and will last much longer with the acids and dirt no longer present to break down the fibers. While washing in plain water will remove many of the acids in the paper which can cause the fibers to break down, chemicals can be added to the water to help deacidify the paper and add an alkaline buffer to the paper (see Deacidification for more information). Washing is the most invasive technique: it changes the paper irreversibly and requires taking the book apart. The decision to wash a book should never be taken lightly.