HP LaserJet 4345 Multifunction Printer series - Printing and paper storage environment

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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

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 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.


Print media specifications


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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 might 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 MFP
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

Paper should be stored at or near room temperature.

The air should not be too dry or too humid (due to the hygroscopic properties of paper).

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