HP LaserJet 4250 Service Manual - Page 44

Paper and print media Category Acid content Caliper Curl in ream Cut-edge conditions Fusing compatibility Grain Moisture content Smoothness Specifications 5.5 pH to 8.0 pH 0.094 to 0.18 mm (3.0 to 7.0 mils) Flat within 5 mm (0.02 inch) Cut with sharp blades, leaving no visible fray Must not scorch, melt, offset, or release hazardous emissions when heated to 200° C (392° F) for 0.1 second Long grain 4% to 6% by weight 100 to 250 Sheffield For complete print-media specifications for all HP LaserJet printers, see the HP LaserJet Printer Family Print Media Guide. To download the guide in PDF format, go to www.hp.com/support/ ljpaperguide. Printing and storage environment Ideally, the printing and paper-storage environment should be at or near room temperature, and not too dry or too humid. Remember that 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. Paperstorage 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 printer performance. The required condition is 20° to 24°C (68° to 75°F), with a relative humidity of 30 1 Product information