The Key to Controlling Color on Flexible Film

Flexible film does a lot more than protect goods on the store shelf. When done right, film packaging design can capture attention and increase product sales. But measuring color on film substrates can be challenging, even for the most sophisticated converter.

Here's what you need to know to successfully control print color on flexible film.

Does your film exhibit interference?

When you measure flexible film with a traditional 45°:0° spectrophotometer, the way you position the instrument compared to the film’s extrusion direction can cause interference, leading to inaccurate readings. Plus, if you change the orientation angle even slightly, the measurement results can change, too, causing even greater discrepancy.

We conducted tests on various flexible film materials to find out just how much variation can occur because of interference. On the most sensitive flexible films, we found changing the position of the spectrophotometer caused deviations up to 2.5 dE*! This can change a measurement from passing to failing, or vice versa.

Here’s how to test whether your spectrophotometer is experiencing variation when measuring on flexible film:

1. Affix the film to an appropriate backing material using adhesive, heat lamination, static, or a liquid layer.
2. Take a measurement and save it as a reference.
3. Repeat the measurement on the same location and orientation several times to evaluate short-term repeatability.
4. Next, rotate the instrument 20° - 30° and take a couple more measurements on the same location. Save as a reference.
5. Compare the color difference between the first and second set of reference measurements. If there is a significant difference, typically 0.3 dE or more, you are experiencing an interference issue.

Be sure to perform this test with any new film. Many films that look the same may in fact have different measurement properties.

The answer to controlling color on flexible film

The eXact is a handheld spectrophotometer for printers and packaging converters to control, manage, and communicate color from anywhere on the pressroom floor. The Xp model, available on the eXact Standard and eXact Advanced, introduces special enhancements that enable users to accurately and consistently measure color on a variety of film substrates, including lamination materials and base structures.

By minimizing the orientation dependency for flexible films, the eXact Xp significantly reduces makeready times, improves quality, reduces substrate and ink waste and creates a more efficient workflow. It includes all of the same features as the rest of eXact Family, including full support for ISO color measurement standards and M0, M1, and M2 measurement modes. The standard eXact also supports M3, which is not needed for film but may be useful in other workflows. Learn more how the M series allows more accurate color measurement of OBA-enhanced substrates in this whitepaper.

Ready to upgrade?

Interested in learning more about the eXact? Read our Which eXact is Right for You? blog. 

If you already own another eXact model and wish to upgrade to the eXact Xp, we offer a conversion path. For users in North America who typically do not use M3 measurement mode (the eXact Xp does not support that mode), we recommend acquiring the eXact Xp for added flexibility if film is part of your business! If you’re new to the eXact family, we’re happy to answer your questions and guide you to the best solution for your needs.

Get in touch to learn more.