What Is The Best Office Digital-Imaging Technology For Printing On Special Media?

It depends.  I know that sounds like a cop-out, but except for printing on multi-part forms (the exclusive realm of impact printers), no single technology is superior to another when it comes to printing on special media.  That’s because there is such a wide array of media and imaging technologies available.

Types of Special Media Used in the Office

• Thick Media – Commonly know as card, index or tag stock (such as meeting placards printed on card stock).
• Thin Media – Media thinner than 16-lb. bond.
• Photo Stock – Thick media coated with a glossy finish.
• Coated Media – Media with a coating that improves image quality, drying time or durability (such as photo stock and ink-jet media).
• Envelopes – There are many types of envelopes; however, let’s stick to printing on common #10 envelopes—a typical business application.
• Labels – Again, there many types of labels; however, let’s stick to (no pun intended) printing on sheets of common Avery #5160 (3 up by 10, bordered) address labels—a potential business application.

Types of Office Imaging Technologies

• Ink-Jet – Drops of aqueous ink are “sprayed” on the surface of the media through tiny nozzles.  Since the media absorbs the ink, drying time is an issue, especially when printing on highly calendared (smooth, non-coated) stocks and when duplex printing.
• Solid Ink – Solid ink is heated into liquid form and applied to the surface of the media through tiny nozzles.  Drying time is not an issue because the ink dries almost instantaneously upon contact with the paper.  This provides a significant productivity boost when printing in duplex mode.  However, since the ink is deposited primarily as a layer on surface of the media, it can be difficult to write on the media.
• Gel Ink – A variant of ink-jet imaging that uses an ink that is more gelatinous than the aqueous inks commonly used in aqueous ink-jet printers.  As with aqueous ink-jet printers, the media absorbs the image, and thus it has better image permanence than prints produced by solid ink-jet prints.  Drying time is superior to that of aqueous ink-jet devices because the ink dries almost instantaneously upon contact with the paper.
• Laser/LED-Array – Particles of toner are attracted to a latent electrostatic charge of the image and then transferred to the media.   Finally, the image is fused into the media through heat and pressure.

Common Problems

Aqueous Ink-Jet Printing

• Bleed-Through – The image from the front side of the media bleeds through to the back of the media.  This is most common when printing with aqueous inks on media thinner than 20-lb. bond.   Image bleed-through is particularly apparent on duplex prints.
• Drying Time – All aqueous inks require drying time, but some ink formulations/technologies require more drying time than others.  Ink that dries slowly can result in blocking (see below) and/or ink smears during the printing, delivery and handling process.
• Duplex Printing – When duplex printing with the typical ink-jet printer, the printer must pause between pages in order to ensure that the front side of the page is dry before printing on the other side.  This seriously hampers duplex printing productivity.
• Printing on Smooth or Calendared Media – Since a smooth or calendared media does not readily absorb ink, drying time suffers accordingly and special handling of prints may be required.  Aqueous ink-jet printers require specially coated label stock with a surface that is absorbent enough for optimum drying time and permanence.
• Image Blocking – In a stack of prints, the insufficiently dried image from one page transfers to the surface of the next.

Gel-Ink Printing

• Smooth, Coated or Calendared Media – Although not as critical as with aqueous inks, the media absorbs the gel ink.  This means that there may be drying-time or permanence issues with some types of media with a smooth finish.

Solid-Ink Printing

• “Write-ability” – Since the ink is deposited primarily as a layer on the surface of the media, it can be difficult to write on.  This is a huge factor for any application that involves users writing on prints, particularly with ball- or roller-point ink pens.
• Smooth, Coated or Calendared Media – Solid ink is deposited on the surface and only partially absorbed by the media.  This means that there may be permanence issues with some types of media that have a smooth finish.

Laser/LED Array (Toner-Based) Printing

• Thick Media Image Feeding and Fusing – One problem is that there can be insufficient heat and/or pressure to sufficiently fuse the toner into the media.  This results in flaking and cracking of the image.  Most printers provide envelope/thick media settings that slow down the speed of the printer during the fusing process for more effective fusing on thick media.
• Coated Media Feeding and Fusing – Sometimes a coating interferes with ability of the toner to bond with the media.  This can result in any number of image-quality and feeding issues.
• Envelope Feeding and Fusing – Due to their unusual size and multi-layer construction, most imaging devices can feed a single #10 envelope.  Other imaging devices can feed small stacks of up to 10 envelopes.  Still others can be equipped with special envelope-tray accessories.  Because of envelopes’ multi-layer construction, some toner-based printers do not fuse properly when the image is printed across the fold.  Consequently, some printers have envelope settings that slow the fuser process to alleviate this issue.
• Image Cracking – When the media is folded, the image cracks across the fold.  Some toner technologies provide superior cracking resistance than others.  With some toner-based printers, there is no alternative other than to leave blank spaces across the sheets in the areas where the folds occur.
• Image Scuffing – The surface of the prints that have a matte finish can sometimes be easily scuffed (with a fingernail for instance).  Prints with smoother finishes help minimize this effect.
• Image Transfer – You’ve seen it and it’s ugly—toner transfers from the surface of a print to the inside of a translucent PVC sleeve.  Some toner technologies are more susceptible than others to this phenomena.  Specialized media and fusing adjustments can minimize or eliminate this issue.

Summary

Printing on special media isn’t all what it’s cracked up to be, especially with toner-based laser/LED-array printers.  If you are unsure about what types of special media your printer can handle, most vendors offer special media that they have tested and/or approved for use with their printers.  Keep in mind however, that some of this special media may be considerably more expensive than generic counterparts.  Hopefully this article will help you choose the right printing technology beforehand and proactively avoid these problems.

Imaging Technology/Media Type

Summary Chart

Happy Reading!
Terry Wirth