Understanding Ink Opacity

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Have you ever had a print job, and the print is just not opaque? Let’s say, for example, a light color print on a dark part. Most customers automatically think the printing plate is the cause, but it’s possible that the printing plate is just fine, meaning that the print issue is caused by something else.

When customers call with this issue, there are a few questions we might ask. Follow our 4 part article series, featuring a few of these questions, along with the reasons we ask them:

What type of ink are you using? Is the ink a standard color or a color match?

It is very important that the correct ink system is being used for the product material. If the ink binder system is not compatible with the product material, the ink may not transfer properly, and in most cases, it might not even adhere when cured. Inks are made up of a resin that is used for specific materials and pigment that makes the ink the proper color; pigments blend better when milled together. Most quality pad printing inks are milled to 3 microns, thus giving the ink more hiding power. If the ink is specifically made for screen printing, the micron size will be larger, thus giving the ink less hiding power when used in pad printing. Screen printing inks are often used due to their more attractive price. Screen printing inks tend to be less expensive because they are milled to a larger micron size; the time to produce the ink is much less, and it does not need to be milled as many times to get the 3 micron size of the pad printing inks.