144 Appendix B Media Specifications EN
Printing and Paper Storage Environment
Ideally, the printing and paper storage environment should be at or
near room temperature, and not too dry or too humid. Remember
paper is hygroscopic; it absorbs and loses moisture rapidly.
Heat works with humidity to damage paper. Heat causes the moisture
in paper to evaporate, while cold causes it to condense on the sheets.
Heating systems and air conditioners remove most of the humidity
from a room. As paper is opened and used, it loses moisture, causing
streaks and smudging. Humid weather or water coolers can cause
the humidity to increase in a room. As paper is opened and used it
absorbs any excess moisture, causing light print and dropouts. Also,
as paper loses and gains moisture it can distort. This can cause
paper jams.
As a result, paper storage and handling are as important as the
paper-making process itself. Paper storage environmental conditions
directly affect the feed operation.
Care should be taken not to purchase more paper than can be easily
used in a short time (about 3 months). Paper stored for long periods
may experience heat and moisture extremes, which can cause
damage. Planning is important to prevent damage to a large supply of
paper.
Unopened paper in sealed reams can remain stable for several
months before use. Opened packages of paper have more potential
for environmental damage, especially if they are not wrapped with a
moisture-proof barrier.
The paper storage environment should be properly maintained to
ensure optimum printer performance. The required condition is 20° to
24° C (68° to 75° F), with a relative humidity of 45% to 55%. The
following guidelines should be helpful when evaluating the paper's
storage environment:
z Paper should be stored at or near room temperature.
z The air should not be too dry or too humid (due to the
hygroscopic properties of paper).
z The best way to store an opened ream of paper is to rewrap it
tightly in its moisture-proof wrapping. If the printer environment is
subject to extremes, unwrap only the amount of paper to be used
during the day's operation to prevent unwanted moisture
changes.
