Opacity mode gap sensor

The MARK•EYE® is a registration mark sensor designed to see printed registration marks on most packaging materials on a continuous web. The “one-touch” set-up enables the sensor to be adjusted with a single push of a button.

The MARK•EYE utilizes a white LED light source that is optimized to detect printed registration marks on translucent and transparent material, and many metalized films and paper. This sensor is particularly useful on form, fill, and seal machines. Note that most packaging materials (except foil) are translucent! Many of the translucent packaging materials that we have tested allow light to penetrate either the backing material or the registration mark. Because this sensor operates in the opacity sensing mode, the color of the registration mark simply doesn’t matter!

Note: Marks as small as 1/16” wide by 1/4” long can be detected, dependent upon web opacity (contrast) and velocity.


  • Detection of color mark on transparent or translucent material
  • Detection of printed mark on metalized film or paper
  • Single, one push-button setup
  • Remote AUTOSET
  • Selectable Pulse Stretcher
  • White LED Light Source 

You can download MARK•EYE brochure (pdf) here »

Here some videos explaining how MARK•EYE works »

You can also find more information about MARK•EYE here »

Please feel free to contact us at any time if you need more information or want to discuss your needs and requests with us.


Tel +358 (0)20 730 6070
Email: sales@kvalitest.com


Tel +46 (0)76 525 5000
Email: sales@kvalitest.com