Events - 2 Aug 2024

Print Techniques – Creasing and Folding

There are many ways to fold a piece of paper: Basic fold (single fold, half-fold, tri-fold.), Accordion or “Z” fold, Parallel fold, Roll fold, Gate fold, Map fold or more complex folds. Each variation offers a unique canvas for creative ideas. The way a paper folds (and unfolds) is an integral part of the presentation of your brochure and should be considered right from the early design stage.

 

  • Fold a board over 170g (140g for Translucents) with prior creasing. Otherwise, it will crack when folding. Creasing will produce a linear depression, to enable the material to be bent (folded) along the line of the crease, thus achieving durable and narrow fold lines with no disfiguring cracks on the printed, varnished or laminated folds.
  • Printed materials should not be subject to dry conditions. Folding quality deteriorates as the moisture content of the substrate decreases. Especially for Translucent papers, the relative air humidity in the finishing and storage rooms should be about 50%.
  • Do not print dark areas or images across the predominant folds, to avoid cracking. With SKIN & Translucents papers, sharp-edged creasing tools must not be used. The creasing rule should be centered on the creasing channel.
  • Avoid UV varnish in areas to be pre-creased. Leave narrow channels in the crease areas.

 

  • Use folding to tell a story with your printed material itself. Folds can control the “reveal” of the message, letting readers take in the first level of information before lifting the fold to move deeper into the story.

 

  • Check the quality of folding during production on a continuous basis. If cracking is evident, stop. An adjustment may well rectify the problem.
  • Fold parallel to the fibre direction, to avoid cracking.
  • Always make the final fold parallel to the grain. Only with Curious SKIN papers are both cross-direction and in-grain folding possible.
  • Fold into the bead. Folding around the bead is likely to produce cracking, the exception being Translucents papers that should be folded away from the bead. Note that Translucents go white when they are creased.
  • Ensure a minimum distance of 4-6 mm between parallel folds -this is essential on 200gsm and above for Translucents.
  • Choose the creasing tool designed to suit the paperboard type and its thickness (usually 2pt). The paper thickness is the most important variable. The crease should be deep and narrow, in order to obtain an accurate fold with low folding resistance. The best creases are obtained by using flat-bed equipment.
  • Use a creasing rule and matrix system to achieve the best creasing characteristics. The width of the matrix is determined by the thickness of the creasing rule (2pt) and caliper of substrate. For boards under 600 microns, the matrix channel width is 1.5 times the thickness of the board plus the 2pt rule. Matrix height is the thickness of the board.