Directionality of Films
I’ve been seeing a lot of discussions online about whether or not certain color change films are directional. I wanted to address this question with regard to the Avery Dennison line of products. Some of this is information that can be used as a general guide for all brands of wrap films, however it is best to consult the product manufacturer if you have questions about a specific product.
What is Directionality?
For the purpose of this blog I’m referring to the color shift or difference in appearance that becomes noticeable when two pieces of film are applied side by side with a differing orientation. Sometimes this difference isn’t noticeable until the vehicle is moved outdoors into direct sunlight.
Some films are more noticeable than others when it comes to the directionality of the film. Specifically for the Avery Dennison Supreme WrappingTM Film line, opaque films seem to be the least noticeable, or not directional at all, and from there films get progressively more directional with pearls being next, then metallics and ultra metallics, with our ColorFlowTM line being the most directional.
I wrapped my truck in ColorFlow Urban Jungle, and I will show you later in this piece just how much the direction of application affects the appearance of the film.
The reason for the directionality has a lot to do with the pigment that is used in the product as well as how the flake is laid down.
How to Apply Film with Directionality in Mind
Let’s start with how it is put down. Who is familiar with the painting process for cars? Ever notice how the painters try to keep the same direction of the paint gun for the entire vehicle, especially when they are working with effects paint like pearl or metallic? If they changed the direction of the paint gun for the fender, it is very likely when you got that car back out in the sun you would notice a slight difference in the color of the one fender versus the rest of the car. This is because the effect pigment is laying a different direction and reflecting the light differently. A casting line is very similar. We are laying the pigment down in one direction for the entire roll of film. If you, the installer, rotate the film 90 degrees, you are changing the orientation of the pigment and changing how the light is reflected.
Now let’s talk about the pigments and why some films are more affected by the change in direction versus others. This has a lot to do with the shape of the pigment. The pigment in opaque films is essentially round, so no matter the angle the light is reflecting the same way and the color appears the same.
When it comes to pearlescent films the pigment used is considered an effects pigment. This starts to flatten out, so it becomes more susceptible to the viewing angle. Certain colors may be more affected than others, and the manufacturing of the effects pigment can vary. This is why some installers comment that Avery Dennison white pearl isn’t directional where our competitor’s is directional.
The metallics and ultra metallics use bigger and flatter pigments, making them even more susceptible to orientation. These films are definitely directional. I have found that as long as you maintain the direction of which the film was cast the colors will match. This means you could rotate a piece 180 degrees and nobody would notice, however if it is rotated only 90 degrees you would see the difference in color.
Check out the purple diamond wrap from Narad Maharaj of Street Dreams Autosport. The door panel was rotated during the install, and they had to redo it so that all panels on the driver side matched.
This photo was shared by Marcos Valente at Wrap Specialties.
Directionality and Iridescent Films
The newly released ColorFlow film is a completely different animal. I can’t go into much detail on how this one works, because it is a proprietary technology. Suffice it to say the pigment we use for this film is very unique in how it reflects light, and it is VERY directional. This film cannot even be rotated 180 degrees, as that changes the way the film looks. Take a look at these photos from my truck wrapped in Urban Jungle. I placed 6″ square pieces in four different directions over my existing wrap. Note that the piece applied in the same direction as the wrap practically disappears where the pieces applied in the three other directions jump out. How noticeable they are changes depending on lighting and viewing angle.
Since the Avery Dennison liner is currently unbranded on the back, it is a little more challenging to keep track of the film direction. We hope to remedy that this year with a branded liner. I recommend marking the back of the liner with arrows to remind you which direction is up. I always keep the roll with the core label as my top side. This way I’m always pulling the film off of the roll in the same orientation. If I have to trim off pieces, I make sure to mark them with arrows, so that I know what direction the offcut piece should be used.
The general rule is to treat all films as directional. If you do this, it is unlikely you will ever run into issues where panels don’t match. If you do have to rotate a panel on a film that is not opaque, you are likely to run into color variances. My general rule is the greater the effect in the film, the greater likelihood you will see a color difference if the film is rotated.
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Written by: Molly Waters, Technical Specialist, Avery Dennison, Graphic Solutions on news.averydennison.com/blog