Hammermill® Paper Pre-printing Guidelines

Design

  • Use offset lithography to preprint material for your printer using heat or thermal resistant inks (see section three - Printing).
  • 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.
  • 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 roller may flatten the embossing.  Embossed designs may also cause double feeding because of interlocked sheets.

Paper Selection

  • Digital printing papers are formulated with xerographic characteristics.  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. to 100 lb. index).

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.
  • If pre-printed material is to be pre-perforated, care must be used in determining the area between the perfs and the locations of the perforations on the final form.  A one to one ratio of perfs and land areas at a rate 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 un 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.
  • 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 advise 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 pre-printed paper passes through the electronic process.
  • Pre-printed 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 pre-printed 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.

Packaging and Storage

  • Make sure material has been adequately dried or cured before wrapping.
  • Package in moisture barrier wrap after drying to protect pre-printed 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 1 1/2" from any package edge.
  • Store wrapped pre-printed material for one to two weeks before using.  This allows extra time for de-curling and minimizes the chance of ink setoff.
  • To maintain quality, store pre-printed material in an environment of 50% humidity.

Recommended Grades

  • Several grades are guaranteed for your pre-printed needs.  Please follow the guidelines in this document for dependable performance of these products on a variety of non-impact printers.
  • Hammermill® Digital Gloss™ Text and Cover
  • Hammermill Color Copy Text and Cover
  • Hammermill Laser Print

International Paper guarantees the performance of these products as set forth above by offering replacement paper or credit for the paper which fails to perform.  International Paper's liability is limited to replacement of the paper or credit in the amount of the purchase price of the paper.  International Paper will not be liable for any incidental or consequential damages.  EXCEPT AS SET FORTH ABOVE, INTERNATIONAL PAPER MAKES NO WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE OF WARRANTY OF MERCHANTABILITY.

©2008 International Paper Company.  All rights reserved.  Hammermill is a registered trademark and Digital Gloss is a trademark of International Paper Company.