Variables like surface tension, media expansion and ink absorption take on new dimensions on larger substrates. If the paper doesn’t advance, it could cause blobs of ink or other ugly outcomes. If the media stretches even a little, you could get blurs. Tiling can become a challenge on larger prints. Read on to discover what to do when ink is not the problem.
You can’t blame ink for all your problems. There are other issues to consider. Discover some other culprits that you may need to address before your next big job.
Ink is ever so important, but you can’t blame ink manufacturers for all your printing problems. If you are having issues with color consistency, fading or blurring, then it’s possible that your media or even your printer should share some of the guilt.
“You’ve got to harmonize ink, media and the printer in order to get the best quality and capability from the ink,” says Xerox digital imaging spokesperson Sandra Mauceli.
“If the inkhead isn’t spitting out in the right directions, or if it is too slow or not functioning properly, you are going to have just as many problems with the image as you would if the ink was too sticky or too liquid, or if there was too much or too little pigment in the ink.”
Maucelli makes some good points, and those are just a few of the many issues that could arise. Are you ready to discover why ink may not be your only quality problem? Let’s get going so we can identify the root causes of printing problem, take corrective action, and up your quality today.
If you’ve been working with wide-format inkjet printers for any length of time, then you are well aware that they are a little touchier than the desktop inkjet printer you use to print out your every day letters and invoices.
For example, variables like surface tension, media expansion and ink absorption take on new dimensions on larger substrates. If the paper doesn’t advance, it could cause blobs of ink or other ugly outcomes. If the media stretches even a little, you could get blurs. Tiling can become a challenge on larger prints.
Then there’s the issue of calibration. May seem like a little fox, but it can certainly spoil the vine. You’ve probably already noticed that the color of magenta from one manufacturer is slightly or maybe even greatly different from the color of magenta from another manufacturer. We’ll talk more about that later. For now, we’ll focus on printheads because experts have plenty to say about how they impact the final product.
Considering the Printheads
Make no mistake, the printheads may be a culprit in your not-so-good-looking banners and prints. Color is an important part of the ink equation, of course. The industry is moving from dyes to pigments and there are new issues to consider in the evolution.
Dyes fade, particularly in ultraviolet light. Pigments, by contrast offer much more stability. Pigments will last for years rather than months. But there is a challenge with pigments: getting them to stay mixed with the carrier.
“If your mixture starts to separate, you end up with pigments in the head or you end up withholding pigments from the paper,” Maucelli says. “And if you pick the wrong carrier for the pigment, you could end up with gummed up inkheads and you will have bad image quality.”
Specifically, you could end up with streaks on the image, especially if you use the equipment infrequently. You need to check with your printer manufacturer to find out how well certain inks interact with printheads and which ones might gum them up or allow the ink to dry on the printhead before it ever gets to the paper.
If you don’t take the time to consider these issues, you could end up with misfiring nozzles or nozzles that are pointing ink in the wrong direction. The latter is a sign that the ink may be too liquid and has too much capability to spread out rather than remaining confined to the area you intend it to cover.
Optimizing the printheads
What Maucelli has been discussing is optimizing the printheads and the ink so there are no surprises on the printed image. In order to aim the printheads accurately, you need to understand the speed of both the printhead and its ink distribution.
If the printhead is moving at the right speed and the velocity of the ink is appropriate, then the ink should hit the paper at the right time and position. (You may have to check with your printer manufacturer for help in this area, but at least you’ll know what to ask.)
“As we go to higher and higher resolution, the capability to aim and hit that bull’s-eye becomes harder and harder,” Maucelli says. “As you are going to smaller and smaller droplet sizes, your accuracy has got to get better.
“When you are dealing with the big droplets like the 40 pico liter drop volume, you can put that in a lot of different places and its going to hit just at the right place, plus or minus,” she continues. “As you get down to the five pico liter size you have got to be really accurate about where you put it.”
Xerox experiments with these types of issues with the understanding that there are so many variables solvents to media to ink brands to inkhead speeds, etc. that you have to optimize on a case by case basis. Getting it right means understanding the technology and designing experiments correctly so that you can optimize your own system (ink, media and printer.)
Armed with this information, you should be able to discern when ink is not the problem. Of course, there are a few other considerations… check back for part two of this article in which we will discuss a few other factors that may impact your ink’s performance.
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