When pressroom production efficiency is an issue—and it almost always is—one of the best places to start adding value is deciding what type of ink is most appropriate for the job and process. What type of ink will help a pressroom run smoother and boost productivity without sacrificing image color and quality? While ink makes up only a small percentage of a print job’s material, it accounts for a major percentage of the success or failure of the finished product. After all, there’s no hiding it: The one thing you and your customers will surely see on any printed item is the quality of the ink.
The fact that today’s press technology makes it possible to print on an ever-expanding range of substrates, from paper to plastics to fabrics of differing weights, densities, absorptive properties, and finishes, only adds to the complexity. Today’s jobs often combine different types of printing processes and require one of a variety of available coatings and laminates as well as postpress folding, stitching, gluing, etc. Because print providers are being challenged with producing a wider range of work on shorter schedules, the ink makes a big difference in the quality of the finished product.
Consider the Job
As a first step in considering what ink should be used, consider the job. Most general commercial printing businesses offer both offset and digital printing (see ‘Hybrid’ article on page 8), and very often they are used together. For example, consider direct mail postcards printed in high volume on offset presses and then laser printed with variable data names and addresses. The offset ink used must work well on the press to make the job profitable and reproduce images and color that faithfully and consistently match the proof, but it must also stand up to the heat generated by laser printers.
Press operators are painfully aware that different presses produce different results, even when using the same inks and substrates. While a well maintained 10 or 15 year old offset press likely is still capable of producing high-quality work, it also probably runs at slower speeds and with less mathematic precision than a brand new offset equipped with the latest in automation.
Additionally, factors such as environmental issues are driving printers to adopt the use of low to no VOC fountain solutions and inks, and also influence the grade and types of substrates that customers specify. Economic reality in many cases compels customers to choose a lesser grade or lower quality substrate to fit their budget constraints. The exact composition of the paper, its absorptive properties, and even the chemical composition of its surface all interact with the ink and can impact the printed result.
Pressroom Efficiency with Ink
While no one type of ink can serve all the different print processes in use today, here are some tips on what to look for in choosing ink and how to get the best results from it.
- Whenever possible, most printers choose a single ink brand or manufacturer for all the work they do, and even for the different types of work they do. Aside from simplifying the ordering process, the reason for this is that printers come to know what to expect from a given brand. Press operators have learned what adjustments may be necessary to get the same results from the ink, even when used on different presses. It is best if a single ink supplier can provide a range of inks, for example offset, UV, inkjet, and varnish.
- Printers should demand a reliable consistency in ink color strength and other properties from their supplier. Because ink manufacturers now purchase ink pigments and other components from sources that may be based all around the world, the quality of these basic ink elements can vary. Look for an ink manufacturer that carefully maintains production standards and processes to ensure consistent quality from batch to batch and can to can.
- To accommodate one of the key variables inherent in every offset job, an offset ink should offer a wide ink/fountain solution window on the most commonly used substrates. This will go a long way toward saving the time required to come up to color, even on different presses and different jobs, will help reduce waste, and will ensure consistent quality throughout the print run.
- The pressroom environment should be controlled in terms of heat and humidity. Heat affects the rate at which an offset ink sets or dries on the substrate, and press operators generally adjust the ink and fountain solution to accommodate as the press runs and heats up. However, the temperature of the pressroom environment can also be a factor and should be monitored. Similarly, ambient humidity affects ink performance as it interacts with the substrate. Humidity also can have a major impact on paper stocks and other absorptive substrates, and this, too, alters ink film lay-down and drying.
- Ink that stays open on press helps to reduce production time and waste by eliminating the need for wash-ups and replenishment of the ink fountains between jobs or even between work shifts.
- To meet particular job specifications, ensure that the ink used accepts, for example, aqueous coating, UV coating, foil stamping, laser imprinting, laminates, etc. This requires a combination of pigments that are resistant to alcohols, amines, and UV monomers; varnishes that have surface tensions that allow for good adhesion; and additives that do not interfere with the transfer or lay-down of coatings or stamps. If the end use of the application necessitates special pigments or varnishes, your ink supplier should be able to produce an ink that is formulated for special situations, including detergent or soap resistance, direct contact with food, or reduced solvent percentages, to name a few.
Versatile Ink Supports Efficiency
Many ink manufacturers, seeking to keep pace with the new technologies and techniques employed in the printing industry, have offered a wide range of ink options. But these options often are intended to work well on a particular type of press or to achieve a particular end result. Finding an ink and/or ink supplier that can accommodate the broadest range of print applications is one of the most effective ways to support pressroom efficiency and productivity.
As you know, every print job is a custom job. Analyzing the specific requirements of every job along with testing new ink products and substrates on the press will lead to the best—and most profitable—results. PN
Joe Bendowski is CEO of Van Son Holland Ink Corporation of America (www.vansonink.com), a leading global printing ink manufacturer known around the world for producing high-quality, high-performance inks. He can be reached at email@example.com.