What Is An Eye Mark And Why Do I Need It?

Eye Mark Sensor for Automatically Applying Labels

An eye mark is a black box that is printed on the edge of the labels, or on the liner, and is read by a machine to know where one labels starts, and the next ends.

This is very common for clear labels, which were introduced in the 1990’s by Crystal Pepsi and Miller clear beer.

The problem was that the label application machines could not find where the first label started, and where the first label ended. Thus the need for an eye mark was needed to tell the label application machine where a label starts and ends. The black box eye mark get’s read by the laser/light on the label applicator.

Newer automatically applied label application machines now use a electric field and not a beam of light to find the start of the labels. The new electric field sensor is unaffected by color or contrast, because it measures thickness with an electric field. The new electric field sensor searches for the difference in thickness, and this is how it knows where the label starts and ends on the liner. Today in 2020 many machine eyes have been updated to use ultrasonic technology which is reliable for almost all label materials.

Clear Labels With Clear Liners and No Eye Mark

Some think that you will always need an eye mark with clear labels, but the truth is that even a clear label on a clear liner, with no eye mark can be applied accurately even at high speeds using the newer sensor technology.

Why Are Eye Marks still used?

The truth is that eye marks are not necessary anymore because the sensor technology has advanced a lot since 1990.

But if you have an old sensor on your label applicator you will need the eye mark.

If you updated your sensor to a newer model that uses an electric field or ultrasonic you can have the option to print your custom labels with no eye markings. Because the newer sensors can detect the change in web thickness without the eye, so you will not need an eye mark on the labels. This will save you money on your private labels because printing an eye mark has an additional cost.  

Do you need a new photo eye to apply your labels? Read more about eye markings here.