This article is part of the FLEXO FLAW FIXING series
What is dot gain?
Dot gain is a printing problem when a picture’s dots are printed too closely together. This can cause the printed image to appear darker than it should and make text and other details difficult to read.
The type of material used, the printmaking setting, and even the paint can all contribute to dot gain.
While some dot gain is average, too much can be a problem. If you’re having trouble with dot gain on your flexo prints, you can do a few things to fix the issue.
How to notice dot gain too high flexo printing issue
One of the most significant issues during flexo printing is dot gain. Dot gain is when the dots that make up the image on the print become more extensive than they should be, resulting in a fuzzy or unclear picture.
There are a few different reasons this might happen, but one of the most common is if the printing plates are not set up correctly.
If the plates are not aligned properly, the ink will not be transferred evenly to the paper, resulting in dot gain.
There are a few ways to tell if dot gain occurs in your flexo prints. First, examine the image closely to see if the dots appear larger than they might be. If they are, then dot gain is likely occurring.
Another way to tell is by measuring the printed image. If the image dimensions are more significant than they should be, dot gain is probably to blame again.
What Causes a Dot Gain Too High?
When the dot gain becomes too high, it can cause the printed image to appear fuzzy or smeared. It can also cause the colors to look muted or washed out in some cases.
This can happen for various reasons, but usually, it’s due to an issue with the printing plates or the press itself.
If the printing plates are not correctly aligned, dot gain could also cause.
If the plates are not cleaned correctly or not stored correctly, dot gain occurs. Another possibility is that the inks are too old or have been improperly mixed.
Incorrect pressure or temperature settings also plays a significant role.
Solutions to Prevent high dot gain problem in flexo printing
If you’re experiencing dot gain issues in your flexo printing, there are a few solutions you can try to prevent the problem from occurring. One solution is to increase the line screen of your printing plate. This will make the dots on your plate smaller, which will, in turn, print smaller dots on your substrate.
Another solution is to use a thinner ink film, resulting in smaller printed dots.
Finally, you can try using a different type of printing plate altogether, such as a digital plate. With digital plates, you have more control over the dot size and can avoid dot gain issues more efficiently.
Here are some solutions that can help prevent these issues:
1. Use a higher-quality printing plate. This will help to ensure that your dots are printed more accurately and with more minor variations.
2. Make sure that your anilox roll is adequately cleaned and maintained. A clean anilox roll will help to ensure that the right amount of ink is transferred to your substrate.
3. Adjust your printing pressure. This can help minimize dot gain and make sure that your print quality is consistent.
4. Use a drying agent or UV curing system. This can help set the ink on your substrate more quickly, preventing smudging and other issues.
5. Make sure that your substrate is adequately prepared. This includes making sure it is clean and free of debris before printing.