HP d640 HP D640 High-Volume Printer - User Manual (Printer and Accessories), C - Page 243

Using Paper Media Selection Specifications and Guidelines Potential Problems Some textures improve paper feeding while others hinder the feed operation. Too smooth or too rough paper can cause a variety of problems in D640 printers. Table D-2 Finish (texture) potential problems Problems Feeding Too Smooth • misfeeds Print Quality • poor toner adhesion • washout will show up (loose toner particles from a previously printed page) • background toner scatter Premature Wear none Too Rough • misfeeds • multi-feeds • poor toner adhesion • light and dark transitions (toner migrates to the valleys of the paper surface, but not the peaks) • printed characters may have broken edges • registration roller • paper path rollers • fuser • paper path guides Felt Side vs.Wire Side The way paper is manufactured results in two-sided paper properties. This, along with other process variations, may make one side of the paper the preferred side to print on. The "top" side of the paper sheet as it is formed is known as the felt side, and the "bottom" is known as the wire side. Most manufacturers indicate the preferred printing side on the package. Moisture Content Note Moisture content is the most critical factor in paper performance in D640 printers. The moisture content of most paper at the time of manufacture is about 4-6% of volume by weight. This percentage can be altered as a result of environmental conditions during converting processes, shipping, storage, and printing. Storage, especially over long periods, can greatly influence moisture content. Because of the hygroscopic properties of paper, unless proper humidity and temperature are maintained, the paper will lose or gain moisture. Using Paper D-7