Digital label printing is no longer some exotic technology that belongs more to the future of label printing than the present. HP Indigo, the leading digital label press manufacturer, recently reported more than 500 press installations worldwide. The company is now one of the top three label press manufacturers in terms of unit sales. In the last two years the number of HP installed presses has doubled and the number of labels printed has quadrupled.
1. Getting business
Whether you have a digital press, a flexo, gravure, screen, or offset press, the most important challenge is always to make sure you have enough profitable business to fill the press time. The additional challenge with digital is that because of its slower print speed you need to focus on the shorter runs. No doubt you will be relying on your sales people to leverage your existing customers, but you will probably need a plan to get business from new customers as well. The good news is that there are many more businesses out there looking for short run labels than long runs, but you need a good sales plan that focuses on these smaller companies in order to get this business.
2. Putting new systems in place
Another huge challenge is how to integrate digital printing into an existing converting operation. If you use exactly the same systems as you do with your flexo press you will be wasting time and resources. The challenge is to implement new systems from sales and customer service all the way through to rewinding and shipping. Digital printing by its very nature is a more lean manufacturing process; there are fewer steps involved in production and less waste. If you are taking more than a week to turn around your digital printing orders, then you either need more capacity or you have too much waste in your system.
You cannot run just any substrate through an HP press; most substrates have to be specially coated before the ink will adhere properly. This is not the issue it once was, because most of the major substrate vendors now have several different choices of material coated for the HP presses. Of course, there is always the option for you to coat the material yourself on an existing flexo press, but that is more challenging than you might think. Different materials require different coatings and there is a lot of trial and error involved before coming up with the right formula. Another alternative is to outsource the coating to a company that specializes in it. Masterpiece Graphix in St. Louis is HP's only certified North American treatment center for coating material, and you can have them coat pretty much any material that you can run through an HP press.
4. Finding the right people
If you expect a flexo operator to jump in and operate an HP press with ease you will be sorely disappointed. HP provides two weeks of operator training at the end of which time your operator should be able to print labels and replace consumables just fine. The challenge he or she will face is in resolving problems (see point 7). It takes a great deal of experience to know just what is really causing the print problems you will inevitably experience. As for what kind of person makes the best operator, there is some debate among HP users. A flexo operator who is good with new technology would work well, but other shops prefer a prepress person who has some mechanical skill. Either type of person should work, but it will be a long learning curve for someone who has little experience with either prepress or press operation.
5. Managing color
As with all presses, managing color is a constant issue on a digital press. The ws4500 press is the best press HP has ever produced as far as repeatability of color, but there will still be some issues. It is important to maintain a consistent operating environment. These presses work best with a constant temperature of around 70°F and a humidity of 40 to 50 percent. If you stray too far from these settings you will get color problems. As with any four color process press, matching a PMS is always a challenge, but HP provides an optional six color process solution called Indichrome (CMYK plus orange and violet) that helps match the majority of PMS colors very closely. The biggest challenge for flexo shops will always be matching color between the digital and flexo presses. Prepress tools from Esko can help with this process, but with two totally different printing technologies matching color exactly will often be very difficult.
6. Integrating with finishing
There are plenty of finishing options available today for the HP presses. You have three excellent solutions that are provided by AB Graphic, Rotoflex and Delta, and these vendors continue to improve their presses. Keeping the diecutting registration is the biggest challenge even with these new presses, and if you have mainly very short runs, swapping dies in and out will slow down your productivity. Also, HP Indigo inks are not particularly durable so you should plan on adding a UV varnish or laminate to most of your labels.
7. Troubleshooting press problems
Why is the press running a little heavy in magenta? What is causing the white spots on these labels? Why is there banding in the dark blue colors? Why can't I match the proof I printed yesterday? There are literally dozens of possibilities to each of these typical press problems. And these problems can drive inexperienced press operators crazy. There is no substitute for experience, and an experienced operator can look at a problem and know the most likely cause. Online user forums such as DICE (Digital Imaging Customer Exchange) and DSCOOP (Digital Solutions Cooperative run by HP) can be really valuable for helping to troubleshoot problems if your operator is stumped. You can search through the archives for your problem and often find a solution on the spot. Or you can post a question to the group and often get a response within minutes.
8. Press maintenance
You can avoid many of the press problems mentioned above by maintaining your digital press properly. To print consistently well, HP digital presses need rigorous maintenance. There are blankets that need changing at least every 50,000 impressions or so, and the photo imaging plate or PIP (the plate that takes the lasered image) also needs to be changed regularly. If you push either of these components your print quality will start to decline. There is a regular maintenance schedule for dozens of other parts that needs to be adhered to as well. Also, adhesive buildup throughout the press can become an issue if it is not cleaned regularly. The challenge comes when you are very busy and it is tempting to skimp on maintenance, but in the long run this will only cause more total downtime.
9. Got database knowledge?
The ability to print variable data is one of the main benefits of digital printing. But to take advantage of all of the capabilities that this provides you need to have someone who knows databases very well. The HP press takes a CSV file as the input database file (which every database program can export to) so you have lots of choices here. Microsoft Excel is the standard here, most of us have it on our PCs and it is easy to get help if you have a problem.
Here are a couple of typical database challenges. A customer may request consecutive labels from A00001 to A19999, but with the even numbers all on one roll and the odd numbers all on another roll. Or it might be that the even numbers repeat three times, and the odd numbers only repeat twice. And the requests can get much more complex than that. You need to be able to set up the database so the variable data job will run both efficiently and correctly — keeping in mind that an error in a sequential run will often force you to repeat the whole job to achieve the required result.
10. Dealing with inexperienced customers
Most label converters have to deal with some unsophisticated or unknowledgeable customers, but when dealing with customers who want only a few hundred labels you are more likely to come across this in your digital printing operation. It is a constant challenge, and one that involves a lot of education by your prepress operators.
We have a document on our web site that points out the most common artwork problems, but we still have to deal with missing fonts, RGB files and low resolution JPEGs every day. We take the time to educate the customer, so when they come back we can get high quality files and go straight to press. Similarly, your sales force and customer service staff have to become adept at dealing with "first timers" who have no knowledge of printing in general, let alone the intricacies unique to labels.
There are plenty of other challenges that haven't been mentioned here, but these are the main issues that everyone will have to deal with in their digital printing operation. None of these challenges are insurmountable and with an experienced staff you might find some don't come into play much at all. Digital printing continues to make advances with each new generation of machines eliminating some of the challenges of the previous generation. By being aware of and dealing with the challenges that do exist, you can take advantage of the many benefits that digital printing provides.