Synthetic Substrates: An Easy Way to Differentiate Yourself in a Complex Market.
By: Steve Gleich, Northeastern Region Business Development Manager at Nekoosa Coated Products

Today, all the major players in our industry, including paper mills, paper merchants and printers, continue to adapt to the growing demand for a wider breadth of printing substrates. Many of these new products allow commercial printers to leverage their new or existing equipment to seek out applications for signage, previously furnished by specialty shops.  Plastic, or synthetic, substrates are gaining popularity because of their extreme durability and resistance to chemicals, water and stains. In many cases, synthetics also eliminate the need for film lamination. Applications run the gamut from shelf-danglers, parking passes and identification cards to menus, flip-charts, recipe cards and manuals.

Historically, printing on synthetic paper was considered a highly specialized process, because conventional offset printers must use specially formulated inks that dry on a plastic sheet’s surface. The related technical adjustments that must be made on press can also be a major burden on the pressman, and disrupt a printing company’s workflow.  Furthermore, resulting dry-times for many jobs are lengthy as well as unpredictable. There can also be complications caused by coatings, varnishes and post-press finishing processes.  You can see why many printers were not anxious to entertain shorter run lengths of synthetic sheets on their offset presses! 

Until recently, digital printing on synthetic sheets was not a good option either.  The temperatures needed to fuse dry-toner caused synthetic sheets to melt, and certainly affected their ability to transport through various machines.

Thankfully, our industry is pursuing new, niche opportunities.  Many new synthetic substrates were introduced to allow commercial printers the ability to best leverage their existing equipment in order to seek out newer print applications. 

But not all synthetics are created equally! There are many options in the market place including polypropylene, polyethylene, polystyrene, poly-vinyl-chloride and polyester base films.  Some name brands such as Yupo and Polyart have been around for a long time, and for certain jobs may be suitable. But in today’s shorter-run, quick-turn, digital age, polyesters are also gaining popularity for a variety of reasons. 

How should you determine exactly what is the most suitable substrate for a particular application?  Where polystyrene will generally be the lowest cost option, it is very brittle and easy to tear.  It also has a very rough surface that will not produce the best image quality.  Where PVC, or vinyl, has better tear resistance and print characteristics than styrene, it normally will require a topcoat or corona treatment to anchor special inks.  PVC, like some other plastics, over time will also breakdown into harmful chlorinated components.

Polyester is among the most durable of substrates.  It has extremely high tear and tensile strength as well as superior dimensional stability.  The heat-resistance of polyester enables transport even through dry toner/laser fusing print devices.  Other film substrates such as PVC are highly prone to shrinkage and distortion when subjected to this kind of heat, causing jams (and also a tendency to melt inside the machine’s fuser section).   Dimensional stability is also an important characteristic for both offset and digital printing when the need to achieve tight registration is especially critical.   Furthermore, polyesters will not degrade into toxic components when landfilled.

Being able to print on a wide range of substrates is a huge differentiating factor for today’s print shop. When considering an alternative to traditional papers, it’s important to be creative!  You may ask whether tear resistance or water resistance is required for the finished piece?  How long will the printed piece need to last?  Will it be used outdoors?  How much will it be handled?  What is the cost differential versus printing on a traditional paperboard grade?  What is the cost differential when compared to printing on a paperboard grade and then film laminating?  Is it to be a static print run or variable data?  Depending on run length, the need may determine whether a sheet engineered specifically for digital printing is needed. 

There are likely many more questions an experienced paper professional will ask depending on the nature of the application, print method and finishing processes required for synthetic printing. The best course is to always consult with your paper supplier.  He or she is educated on the advantages and limitations of many product offerings, both old and new. Mastering synthetic printing is a great way to differentiate all players in our industry, and we will continue to see further innovations as demand for these products increase.