How it Prints

Polyart® adapts quickly to most printing processes, such as flexography, lithography, gravure, rotary letterpress, screen, as well as variable information systems such as thermal transfer, ion deposition, dot matrix, ink jet, etc.

Polyart's clay coating is responsible for its ability to readily accept color - and show it off beautifully. 
Polyart ensures rich, vivid images with excellent ink holdout without requiring special preparation.

Printing Tips

Inks

  • Use litho inks (which have low mineral oil content) and control ink/water balance.  You'll get the same printing result with minimum damping and less ink film.
  • With lighter basis weights, use special inks with very low mineral oil content that are allowed to dry entirely by oxidation.
  • For best results, consult with your ink suppliers.
  • For both heavier and lighter basis weights, print on the dry side while maintaining good ink/water balance.
  • Ink tacks should be in 16 tack or below.
  • Multi-color work is best achieved when printed in a single pass on a multi-color press.

Proofing

  • Where possible, practice undercolor removal in wet-on-wet printing (to keep film weight down).
  • Use minimum ink weight in solid area

Drying

  • Ink is usually run straight from the can.
  • In some instances, may need to include small amount of non-mineral oil reducer. (Consult ink manufacturer in these cases.)
  • Successful results can be achieved using UV drying techniques with appropriate UV inks, as well as electron beam and infrared drying techniques.
  • Oven temperature should not exceed 74°C / 165°F. (Maximum web temperature 38°C / 100°F)

Stacking

Heights of approximately 500 sheets (5 inches / 13cm or less) are recommended.

Feeding

Polyart will feed just like a matte-coated paper on all types of feeders. Ensure that sheets are aired (fanned) prior to printing.

Anti-Offset Spray Powder

  • Should be used during printing by litho and letterpress. 
  • With heavy four-color process and/or solid background work, use non-vanishing, starch-based offset sprays of small particle size (25 microns and above ≈ .5 to 1 mil). 

Humidity

Keep pressroom humidity levels at 45-60%.

Varnishing

For varnishing with machine and waterbased systems care should be taken to allow varnish to dry to a hard finish. If using aqueous coating on both sides of the sheet, it is recommended that a coating suitable for double sided working is used. Where Polyart has been pre-printed prior to UV varnish being applied, it is very important to remove all anti set off spray powder to prevent speckling in the finished UV varnish. Where non UV inks are to be varnished, the inks should be wax free to prevent bleed. To prevent material distortion form UV source, only minimal power should be used to cure the varnish.

Small Offset Machines

  • Keep the proposed end-use in mind when selecting inks. (For example, light-fast inks must be specified for prints to be exposed to sunlight.) 
  • Synthetic oxidizing inks are recommended.

Litho & Letterpress

For best results, use screen sizes of up to 175 screen.

Polyart Digital on HP Indigo digital presses

Polyart is available in a range of HP Indigo certified substrates qualified for use with both sheet and web output devices. Ensure that the sheets have been aired and fanned before loading into the feeder. As with all synthetic papers and films, it maybe necessary to carry out one or more null cycles, as well as blanket shift separations for correct CPR control to obtain optimum print register.

Polyart 20 pt. / 405 g/m²

  • Printing is very similar to regular lower grammage/weight Polyart sheets, some adjustments to the blowers on the feeder maybe required due to the higher weight of the sheets. Carton grade types of inks can be used but we would recommend non vanishing type anti set off spray powders of 50 micron particle size. Stack heights in the printed delivery will be dependent on the ink drying system; both IR &UV will allow the same stack heights as carton printing, but non assisted drying inks will require smaller printed stacks. 
  • Over varnishing can be carried out both inline and off line as required, no issues with die cutting, although it is essential to keep all tools sharp to avoid any nicks on the edges and to use round corners to avoid any risk of tear problems arising. During any folding operations, we would recommend to carry out pre creasing. Any folding or creasing where a UV varnish has been applied may cause the cracking of the varnish.

Polyart Iridescent Printing Tips

pdf, click to download

Advice in this page is based on practical field experience and given in good faith but Arjobex may not be held liable for loss or damage arising from action based on this information.