We all know that paper isn’t exactly one of the most waterproof materials out there. In fact, water exposure is one of the most common causes of damage to paper objects that I see as a paper conservator. It can cause major issues such as distortion, staining, loss of media, and mold, just to name a few. It’s somewhat counterintuitive, then, that water is a crucial part of many types of conservation treatment. People are often a bit shocked that bathing paper (yes, it’s what it sounds like) is a common practice with positive results! In this post, we will explore a few ways in which water interacts with paper on different levels, how conservators harness and leverage these interactions to treat condition issues, and how, if left unchecked, these interactions can cause major and irreparable damage.
Papermaking – Wet Beginnings
To understand paper’s relationship with water, we have to go back to the beginning – papermaking. True paper is defined as a non-woven mat of fibers formed by draining water from a slurry. The water holds the fibers in a suspension into which a screen called a mold is dipped and drawn upward, allowing the water to drain and the fibers to settle into a layer over the screen. To ensure an even distribution, the mold is shaken back and forth while the water drains, causing many of the fibers to orient in the direction of the movement before coming out of the water. This causes a characteristic called “grain” in a finished piece of paper.