My name is Gregory Daerr and I have been installing and servicing large-format digital printers for more than 17 years. I own www.at-yourservice.org and service the Southern California area. My services include training, service/repair and installing printers as well as ICC profile creation to name a few. It’s my goal to use this experience to help benefit and empower our readers.
This month, I have prepared some easy reading, but as we move forward it’s my goal to get more technical as we build on what we have learned. My hope is that you can use this knowledge to save expenses and better understand your printer. We will cover everything from do-it-yourself maintenance to tutorials about how to get more from your software. I hope you find this helpful, and I encourage feedback and questions.

Eco-Solvent Printer Basics
There are a few things you can do to get the best image quality out of your printer. Many of these things are mentioned in your user manual or other associated documentation that may have come with your printer. Some of you may have been shown these procedures during installation. It surprises me, however, how many people either forget or were never shown. I think a refresher could help many.

Here is an example of a good test pattern. All the nozzles are firing correctly without any gaps or “deflecting” nozzles.

This is an example of a test pattern that is not acceptable. Cleaning is required.

Before you do anything at all, it’s important to make sure your printer is firing all of its nozzles. If not, perform a cleaning until they are. I know to many this seems like a basic procedure, but over time people can become complacent. It’s worth doing a test print and any necessary cleaning on a daily basis to maintain print quality (See photos above). Many printers will have a cleaning button placed right on the front panel, and in some cases it will be under the main menu. Either way, consult the user manual. It will have instructions on how to perform a cleaning. This process is similar to how you might clean a desktop printer.

I should note that it is possible to print (get passable print quality) with up to about 10 percent of your nozzles missing, but you will likely have to double the number of passes for your printing and possibly increase your print resolution in order to compensate. This is done in either the RIP or on the printer. Even though you may be able to compensate, it is important to note that if you fire the head like this for too long, you may permanently clog those nozzles or risk damaging or overheating the head. Either way, it’s always best to try and do what you can to clean any clogs as they come up.

Heaters: Heaters are used in solvent printing to assist with the curing and adhesion of the ink. Because we’re using (in most cases) uncoated media, we have no way to control how much each drop of ink will wick or bleed into each other. Too much heat and the images will look grainy and textured. Not to mention the risk of media reaction to this heat, which may cause it to “buckle” or “blister” and cause possible damage to your print heads.
On the other hand we must be careful to make sure the temperatures are not too low or the ink will bleed and look out of focus or blurry.
To make sure you have the proper temperature, start off with around 40 - 45 degrees Celsius and slowly raise the temperature until you get a crisp test pattern, which should also be dry to the touch.

Note: Some media will have thicker backing, which serves to insulate the media from the heaters. Be careful if you see your media “bubbling” when you are adjusting the heaters because it may be a sign that that media may not be the best choice for use on your printer. The surface of the media needs to be around 45 degrees Celsius for it to catalyze with the ink.

Head height: Head height is a commonly overlooked feature by many users. What does it do? To start, it can help you get crisper edges on your prints or, in many cases, eliminate “overspray” issues. Print heads require a certain distance from the media to get optimal quality. If your head height is set too high, you get blurry, misaligned images. Too close and you risk having your print heads strike the media or excessive backspray buildup. Both of which can easily call for replacing a print head.
To avoid these problems, most printers have at least two head height positions: low/thin or high/thick. Some have a “middle” head height as well, but the most important thing to remember is if you’re using thin materials such as adhesive backed vinyl or paper, then you want to use the lower head height positions. If you’re running thick banner vinyl or even laminated material through your combo printer/cutter, then you must use the highest head height settings.

Important note: Make sure to check your head height before printing. Using too low a head height on thick media can damage the print heads.
By making sure you have the correct head height, you not only assure good print quality, but you prevent unnecessary overspray or head strikes, which in the end can reduce maintenance costs. Print heads should last around five years if you take care of them and perform regular maintenance. We will cover this more in future articles.

Feed correction: On many Roland printers this is called Printing Adjust. On Mutoh printers you will see this called Distance Adjust and Mimaki printers usually file this adjustment under Media Comp. (compensation). I am just naming a few of the most common eco-solvent printer manufacturers here, to cover them all would be beyond the scope of the article, but I hope you get my point, which is: They are all the same thing.
Feed correction is designed to make sure that there is minimal banding when you use different thickness materials. How far the feed motor feeds the material is determined by this calibration. Without it, you could spend all day playing with other settings trying to get more consistent output and end up frustrated.
What we do here essentially is print a pattern stored on the printer. Some printers print small blocks on top of each other and depending on the distance between these blocks, we make adjustments in the feed distance. If the blocks overlap, then we need to increase the feed distance with a positive value or in the case of gaps in the blocks, we decrease the distance with a negative value until we can see little or no seam between the patterns.

This is an example of a Feed Adjustment pattern. Notice the left pattern is slightly overlapped. The pattern in the middle has an ever so slight gap, and the right pattern is just right. It looks like a “T” or a single pattern, instead of two blocks on top of another.

Again, if you were not shown this procedure, it is in the user manual and it deserves some attention. Many operators will play with heater settings until they see a reduction in the banding, only to see the problem return. Either way, image quality suffers unnecessarily.

Software: Software can cause all sorts of headaches if you don’t have it sorted out. Remember that the software almost always overrides the hardware settings. That means that if you have your feed correction and heater settings all configured on the printer, but fail to check your driver settings in the software, it’s possible to print your work using the wrong settings. Many software packages will have an option to turn the control over these settings off or on.
If you’re not aware of this, it can be terribly confusing. As a general rule, I recommend that you change your settings in either the RIP or on the printer and never deviate. Especially if more than one person operates the printer.

These steps are simple and easy to remember. Just a few minutes each day before you begin printing is all it takes. As we move forward, I would like to invite you to write to me with some of your technical printer issues and we will share your experiences. I will offer some help for you and other readers to benefit. My goal is to create a monthly dialogue where I can answer these questions and offer tips on anything our readers may want to know about with regard to large-format digital printers. We hope that you will share with us. Please e-mail me at gregorydaerr@at-yourservice.org.