By Olivia Cahoon
Digital printing consists of two primary methods—inkjet and electrophotographic (EP), which includes liquid (LEP) and dry inks and toner technologies. Both offer benefits and challenges that typically depend on the print provider’s needs and operation.
One significant advantage to EP/LEP compared to inkjet is that it is a more mature production technology and therefore is supported by a variety of media options. These substrates range from standard copy paper to polyester, polypropylene, and specialty offerings like magnetic and metallic paper.
EP/LEP Media Options Improve
Advancements in heat stability are important to enable different media for laser, EP, and LEP production print. This includes a variety of specialty options such as carbonless paper, fine art papers, labels, metallic paper, pressure seal forms, synthetics, and specialty packaging.
Depending on the end use of an application, print providers utilize inexpensive office copy paper and get adequate results in EP/LEP production printing. However, achieving optimal performance may require specialty papers. Additionally, using inappropriate media may damage laser printers, shares Fabrizio Mandingorra, labels and print global segment manager, PPG TESLIN.
Synthetic media options are limited due to the high heat in the EP print process. “It is broadly accepted that you can’t just run any synthetic through any digital press and you must use a media compatible with your print engine,” says Mandingorra.
The key factor is in the media’s heat stability. Certain substrates like polyester can run as high as 350 degrees Fahrenheit without a problem while others like polypropylene and high-density polyethylene start softening at 220 degrees Fahrenheit. “You don’t want to chance damaging your machine and possibly voiding the equipment warranty,” warns Mandingorra.
Technologies have improved in the past few years so that many specialty media products such as plastic and adhesive synthetics work well on most color production devices. Rick Keber, director of offset and digital media, Midland Paper, notes that media traditionally used for offset printing is now available in some form for digital presses.
Print providers capitalize on number of available EP/LEP substrate options and add value to their print operations by using unconventional media, taking advantage of aesthetic and tactile aspects, and utilizing sustainable options.
Every time a print provider selects media there is a cost/benefit decision that depends on the job’s requirements. “Today users have a range of media options that they can switch between regularly depending on how the printed piece is used and under what conditions,” says Mandingorra.
The range of compatible media combined with EP/LEP technology’s flexibility for smaller, urgent, and customized jobs expands printers’ workloads and how they differentiate themselves from the competition. According to Mandingorra, customization and variable data presents opportunities for print providers looking to stand out.
Synthetic media is known to be tough and versatile, making it ideal for EP print applications that range from printed laminated materials such as identification, insurance, and customer loyalty cards to waterproof maps, menus, wristbands, racing bibs, temporary license plates, and durable labels.
Print providers sometimes capitalize on available substrate options by searching for and testing products that might be typically unconventional for a digital sheetfed press. Keber says this includes synthetics such as polyester, PVC, polypropylene, and some poly blend media.
Further, Julie Brannen, director of sustainability solutions, Monadnock Paper Mills, Inc., believes the ability to mix coated and uncoated substrates on a project gives marketers many more design choices. “With higher quality substrates, print service providers get better efficiency and better print results.”
Print providers add value to a printed piece with the right media, bringing aesthetic and tactile effects to the table to stimulate the end users’ eye and touch while adding significance to a marketing and sales campaign. “The added value of printed communication is related to the power of engaging multi senses, boosting the message, and the results of using print quality,” says Andrea Favini, export sales and marketing director graphic specialties, Favini.
Sustainable media options also impact the market. By providing sustainable media, print providers can offer value to today’s high-end retail, hospitality, and corporate marketers, shares Brannen. “Many companies have adopted sustainable purchasing guidelines calling for high recycled content papers.”
Hitting The Trends
Trendy new substrates help print providers remain competitive and relevant. This includes board stock, eco-friendly options, sensory boosting papers, synthetic products, and luxury options.
Several trends have occurred over the years, including new global government regulations and more environmentally conscious consumers. Mandingorra says this results in a continued and heightened focus on sustainable print solutions from recyclable, biodegradable, or compostable ink and media help reduce energy use and raw material sourcing and utilize environmentally responsible supply chains.
“There is an increasing interest in ecological papers, produced according to circular economy principles,” agrees Favini. Options include products composed of seaweed, agro-industrial byproducts, and residues from leather and textile production.
Another major trend includes substrates that offer a sensory appeal. “Brands increasingly seek to connect with customers through tactile elements, unique visual, functionality, or even smell. The goal is to grab their attention and draw them to interact with a printed piece,” offers Mandingorra.
Synthetic papers are trending due to the need for print pieces to be long-lasting, durable, and to withstand harsh conditions. According to Mandingorra, companies choose synthetic paper because it will not deteriorate when exposed to rain, humidity, extreme temperate changes, abrasion, or scuffing.
Board stocks pre-treated with soft touch coatings are new and popular. Keber says applications include business cards, book covers, invitations, sell sheets, and greeting cards. This product eliminates the necessity of coating offline to create a soft touch effect.
Because digital printing technologies are ideal for short run, high quality, and high-value applications, the luxury market benefits greatly. A range of luxury material labels are available—specifically for HP Indigo—and are trending such as iridescent, gold, silver, and pearl white, which are particularly successful in the luxury car industry, shares Louis Rouhaud, global marketing director, Arjobex America. These grades are also available as facestocks for labeling.
Another field is security documents, which involve substrates with embedded features for theft protection, tamper evidence, and anti counterfeiting. According to Rouhaud, this makes the substrate an ideal platform for all kinds of sensitive documents or labels. “Security features include visible or invisible UV fibers; we can also add taggants, making it level two security—ideal for certificate or diplomas, anti-diversion, or government documents.”
Testing New Media
Print providers should always test new media to avoid complications and ensure compatibility with a press.
“Everything from image clarity to color vibrancy and scuff resistance, and product life are affected by the kind of paper you use,” advises Mandingorra. Therefore, print providers should always check with the printer manufacturer and media supplier to understand if the material is compatible with the printer and what setting is needed to achieve optimal results.
Arjobex extensively collaborates with OEMs to test and certify its media. Additionally, print providers can ensure select substrates are compatible by viewing their press media locator, which assists in locating the best substrates for printing.
However, not all OEMs have media locators. In this scenario, Rouhaud suggests print providers connect with the media manufacturer for samples or guidance. For general printing advice, technical data sheets are available on most media manufacturers’ websites.
Compared to Inkjet
In regard to media, there are benefits and limitations to EP/LEP technology when compared to inkjet. By looking at both strengths and weaknesses, print providers decide which technology works best for their desired media, print operation, and customers.
While inkjet printing presses are popular in both web and sheet varieties, Keber believes that unless they have UV drying capabilities, running non-porous substrates such as gloss paper and synthetic media is problematic with inkjet technology. “Dry toner and HP Indigo devices have the ability to deal with a much larger range of materials, which can be setup and run in an extremely short amount of time. And the quality of the image is very high.”
Rouhaud agrees and believes print quality is a primary advantage of EP/LEP media, followed by the ability to serve short-run, high-quality offset markets.
Additionally, media designed for EP/LEP doesn’t typically require specific surface treatments and coatings like water-based inks. “Dry toner can still be on the high side in temperature, and can limit the synthetic substrates available; LEP producing less heat offers a wider range,” offers Rouhaud. While UV inkjet solves this issue, he believes there it still room for improvement in print quality.
Dry toner technology allows printers to utilize standard materials without primer, which means there are more materials available, agrees Paul Lender, business development manager, digital, Avery Dennison. It also offers robust performance on a range of materials.
Lender believes LEP ink is not as robust, so an overlaminate is often required to build durability. In this scenario, he feels print providers should use a primer coating whether performing inline or buying pre-optimized materials.
While EP/LEP technology seems to currently have more of a media selection available, inkjet is constantly evolving and closing the gap both in terms of substrate options and product quality on more demanding print jobs, adds Tyler Sukeforth, brand manager, coated paper, Sappi.
Additionally, dry toner is typically limited in sheet size and speed. This is partially solved by LEP, which has larger presses. “Digital is meant for low-volume short runs, but with the converting equipment largely available in larger sheetfed offset sizes, it makes sense to have large sheet sizes,” suggests Rouhaud.
Several substrate providers offer specific solutions for toner- and EP/LEP-based print engines.
Arjobex specializes in synthetic paper. Its most popular offering, Polyart, is designed to look, feel, and print like paper with the water resistance and durability of a synthetic. Arjobex develops proprietary matte coatings to give synthetics the specific look and unique touch of paper for all digital technologies, including EP, LEP, and inkjet.
Avery Dennison provides pressure-sensitive and non-pressure sensitive materials for the EP/LEP print market. For the laser/EP market, it offers sheetfed paper products such as Laser Code and DSX products built with layflat liners. Avery Dennison’s LEP pre-optimized portfolio is an extensive line with over 50 options available, including a range of paper, film, and foil solutions.
Boise Paper, a division of Packaging Corporation of America (PCA), offers rolls and sheets specifically intended for use in commercial grade digital printers.
Favini offers fine art papers dedicated to digital printing with two specific lines for the EP and LEP print market, both available as cut to size. The DIGITAL collection includes popular Favini papers such as Biancoflash Premium high-quality white paper, Bindakote cast-coated paper, and Majestic, which is available in four metallic shades. The product line for LEP equipment includes felt marked grades Twill and Prisma and the 100 percent recycled ecological paper, Shiro Echo.
Among International Paper’s digital offerings is Accent Opaque’s Indigo Treated Digital papers. These solutions are specially formulated to run on HP Indigo presses. These sheets are well suited for merchants, graphic designers, and commercial printers looking to impress with their booklets, catalogs, manuals, brochures, direct mail, financial documents, reports, posters, flyers, sell sheets, invitations, greeting cards, menus, tent cards, and marketing materials.
Midland Paper provides sheetfed coated paper, uncoated papers, and specialty text and cover papers for HP Indigo and dry toner technology.
Monadnock Paper Mills, Inc. offers a range of premium uncoated and coated two-sided 100 percent post-consumer waste recycled fiber substrates for the EP/LEP production process. This includes Astrolite PC 100 Digital+ uncoated and Astrolite PC 100 Velvet C2S coated two sides—both HP Indigo 3-Star Certified. All products in the Astrolite PC 100 line have a matching shade and are available in a full range of sizes to accommodate digital sheetfed presses.
PPG TESLIN provides a variety of digital papers for laser and dry toner. Its Lumit Digital paper is a polyester-based synthetic print sheet optimized for high-heat, dry toner laser print applications. The digital paper is smooth and rigid, UV stable, and highly resistant to heat, moisture, tearing, and various industrial chemicals. Available from two- to ten-mil thicknesses, Lumit is suitable for a variety of specialty printing applications such as die cut labels, grocery store signage, horticultural tags, menus, retail applications, and ticket passes.
Sappi’s McCoy Digital sheets are designed for HP Indigo presses. The sheets are available in gloss and silk finishes in a variety of weights and opacity levels. McCoy Digital is often used for applications like brochures, direct mail, and personalized end uses. All McCoy products feature ten percent recycled fibers.
This is just a sampling of the media options available to EP/LEP presses. Please see the following resource guide for a more comprehensive list of media providers for this segment.
Media selection is a crucial part of the print production process. For EP/LEP print engines, special substrates are essential for optimal results. Print providers can capitalize on the range of available substrates, but it is critical to properly test new options before use. dps
May 2020, DPS Magazine