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Williamsburg
1. Letterhead and Form Design
- Use offset lithography to preprint material for your printer using heat or thermal resistant inks (see section three - Printing).
- Design the letterhead or form so that it conforms to the grain direction specified in the laser printer user’s manual. Most high speed laser equipment requires grain long, but some slower printers specify grain short.
- Eliminate large solidly filled areas of ink, if possible. Toner does not adhere very well to heavy coverage areas. If solid areas must be used, break them up with fine-screen halftones.
- Keep it simple. Include only necessary information.
- Thermography should only be considered with powders specially formulated for use with laser printers. These powders require special curing (UV or heat) to harden and will not re-melt or cause contamination.
- Avoid hot stamping and similar techniques. Fuser heat may melt the foil, causing discoloration or costly machine repairs.
- Avoid blind embossed logos. These will not cause damage, but the fuser roll may flatten the embossing. Embossed designs may also cause double feeding because of interlocked sheets.
2. Paper Selection
- Laser papers formulated with some xerographic characteristics are recommended. These papers have special properties, which assure optimum laser printer performance.
- Check the equipment manual before specifying paper weight. Some laser printers require 20 to 24 lb. paper. Others accept a very wide range (16 lb. bond to 100 lb. index).
- Paper with a smooth, level surface shows off laser printing to its best advantage. There are no "hills and valleys" to mar printer output.
- The paper must be precisely trimmed and cleanly cut. Improperly trimmed paper with welded or ragged edges can cause multiple and skewed feeds, dusting, internal jamming and other performance problems.
- Avoid heavily embellished finishes (e.g., embossed, laid and other textured finishes). Toner does not get down into the valleys of their irregular surface, producing broken letters and uneven images.
- Regardless of the type of paper used, make a small test run before printing the entire job. Several factors and variables can affect the printer and printing process. Make sure the paper used is recommended by the printing manufacturer.
3. Printing
- If only one side of the form or letterhead is to be printed, offset printing should be done on the wire side of the paper.
- When printing large sheets of rolls, final trimming of the form must be clean, square and true to size.
- If pre-printed material is to be pre-perforated, care must be used in determining the area between the perfs and the location of the perforations on the final form. A one to one ratio of perfs and land areas at a rate of 9 perfs per inch is preferred. The perforations should also be rolled to prevent problems in the feed and delivery areas.
- Material with micro perfs runs well through laser printers. This process differs from standard perforating. Micro perfs are very flat and a greater number of perforations per inch are used (72, 50 and 30 perforations per inch are generally available).
- To prevent jamming on printers that feed the long edge first, full-length perforations parallel to the long edge should be no closer than 3" from the leading edge.
- Laser compatible inks are required. Do not use coldset, conductive or rubber based inks.
- Select litho printing inks, for pre-printed letterheads and forms that can be subjected to temperatures of up to 400F, pressures of up to 140 psi and a dwell time of 30 to 35 milliseconds throughout the fuser section of the laser printer. (Ask your ink manufacturer for advice about the thermal resistant inks that oxidize and polymerize well on paper.) These inks should run through electronic printers without causing contamination problems.
- Minimize the amount of ink and fountain solution used to reduce the possibility of "wavy" paper.
- Keep ink coverage, color density and the number of colors to a minimum. Each color impression introduces additional moisture, which can cause cockling when the preprinted paper passes through the electronic process.
- Preprinted forms must be free of anti-setoff powder and spray. Both can inhibit imaging and fusing operations. They can also cause damage and breakdowns by forming deposits throughout the system.
- Allow preprinted material to "cure" before packaging. Maintain 50% humidity in the storage area, if possible. Cover stacks with plastic sleeves as they are staged for curing and packaging. This will protect the paper from stress induced by changes in humidity.
4. Packaging and Storage
- Make sure material has been adequately dried or cured before wrapping.
- Package in moisture barrier wrap after drying to protect preprinted stock from changes in humidity during shipping and storage.
- If a plastic shrink wrap is used, avoid crimping or curling damage to edges or corners by making sure the wrap is not too tight. A piece of chipboard on both the top and bottom of the stack will also help you avoid this problem. Locate air exhaust holes at least 11/2" from any package edge.
- Store wrapped preprinted material for one to two weeks before using. This allows extra time for de-curling and minimizes the change of ink setoff.
- To maintain quality, store preprinted material in an environment of 50% humidity.
5. Recommended Grades
- Several grades are guaranteed for your pre-printed needs. Please follow the guidelines in this document for dependable performance of both products on a variety of non-impact printers.
- Accent Opaque
- Accent Opaque Digital
- Williamsburg Offset PLUS
- Springhill DIGITAL Index
- Springhill DIGITAL Vellum Bristol Cover
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Printer Friendly Version
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