Moisture Content - What is moisture content?
A measure of how much moisture or water is contained in paper. Paper has a strong affinity for water because it is made up of cellulose fibres that are hygroscopic; the fibres readily absorb or release water in order to gain equilibrium with the humidity of the environment. Moisture content is expressed as a percentage of the original weight of the paper.
The dimensions, lay flat, conductivity, strength, and printability of paper can all be affected by moisture content. Fibres expand or contract as they absorb or release water - more so in width than in length - meaning that the paper will be altered most clearly against the grain. The grain is often more pronounced on the wire side, meaning that moisture content will also change unevenly, causing the paper to curl. Dry paper will tend to tear more easily and is likely to produce poorer print results, particularly with toner, which may not bond properly to dry paper.Go Back to Glossary