Percentage of moisture in the office paper is a critical indicator for working properties of paper. Usually office paper has lower humidity (about 4.2 to 4.5%) than offset paper (about 5.0 to 5.5%). That is because the office paper is exposed to significant heating in almost all models of copiers. Having low humidities, paper is more stable during the changing of the size and geometry, and less exposed to temperature extremes. Thus, the paper is less likely to twist or wrinkle under the influence of the picture transfering process, and we get a more compact / dense stack of paper to be published.