HP Color LaserJet 4730 Multifunction Printer series - Manual (Page 380)

Print media specifications
This section provides specifications for media that can be used in this MFP. For more information, see
Printing on special media .
Category Specifications
Acid content 5.5 pH to 8.0 pH
Caliper 0.094 to 0.18 mm (3.0 to 7.0 mils)
Curl in ream Flat within 5 mm (0.02 inch)
Cut edge conditions Cut with sharp blades that create no visible fray.
Fusing compatibility Must not scorch, melt, offset, or release hazardous emissions
when heated to 200°C (392°F) for 0.1 second.
Grain Long grain
Moisture content 3% to 9% by weight
Smoothness 100 to 250 Sheffield
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 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 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 environment:
● 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 MFP environment is subject to extremes, unwrap only the amount of paper to be used during
the day's operation to prevent unwanted moisture changes.
360 Appendix E Media specifications ENWW