If there’s one area nearly every sign shop and digital printer wants to get involved in, it’s the fast-growing vehicle wrap market. More and more companies, transit systems, and even individuals are using these eye-catching mobile billboards to get attention wherever they go.
Cast or Calendered?
Full knowledge of a vehicle’s condition is critically important for selecting the right vinyl for the wrap. You’ll need information about the vehicle’s size, the age and condition of its paint job, and the presence of problem zones such as plastic overlays, curved surfaces, and rivets. Based on this, you can determine whether you should use a cast or calendered vinyl film.
Calendered vinyl films are typically lower in cost, relatively strong, and can provide the advantage of being robust and easily removable on vehicles without challenging surfaces or problem zones. These films can be used successfully in applications consisting mainly of flat surfaces or simple corrugations such as panel trucks. They can also be used without lamination for short-term promotional applications if your budget is tight.
Cast films, however, are the product of choice for longer-term applications or more complex surfaces. Their composition and construction allow application with a heated deep-drawing process for increased conformability over and around problem zones commonly found on passenger vehicles, SUVs, watercraft, ATVs, and motorcycles. These thinner films are typically used with a matching cast laminating film to provide adequate strength and body, and to provide long-term protection against ink fading—caused by UV rays—as well as mechanical and chemical abrasion.
Measure Twice, Print Once
Make sure you have accurate measurements of the vehicle. There are software packages that provide templates of almost any make and model vehicle made. They’re great for setting up and designing your graphic to ensure that important parts are not lost in a door handle or distorted on a complex curve.
If you will receive your graphic from a design agency or directly from the customer, have them provide the original file with layers to make it easier to move images as needed to accommodate the vehicle. It is important that the file be at least 300 dpi or larger to enlarge the artwork to full size prior to printing. For the final full-size print file, a resolution of 72 to 125 dpi is adequate. This smaller image size will help speed the RIP process, and make the file easier for your computer to handle.
Once printing is complete, it’s best to wait at least 24 hours before laminating to give the inks time to cure and outgas. If the laminate is applied too soon, solvents can outgas through the printed image, which can make the adhesive much more aggressive during installation.
The day before applying the film, the car should be taken to a car wash that uses brushes to remove as much road grime and other surface containments as possible. After, thoroughly inspect the surface and edges for any remaining wax, polish, grease, or grime. Any such substances must be removed using industrial cleaners or silicone-based detergents. A final cleaning should be done with isopropyl alcohol to remove any leftover impurities that could hinder the adhesive. Before using any solvent on a vehicle, be sure to test in an inconspicuous area to ensure it will not damage the vehicle’s paint.
The next step is to remove any vehicle parts that may hamper application, such as mirrors, trim, or wiper blades. Check and clean any surfaces uncovered in this process by following the steps described above.
It is very important to allow the vehicle to dry completely after cleaning it. It can take up to 24 hours for a vehicle to dry fully, especially in humid or cold conditions and beneath trim areas. This may require allowing the vehicle to dry indoors overnight.
Whenever possible, apply graphics indoors in a controlled environment. Doing so will not only help you control the temperature—ideally between 71°F and 73°F—but will also reduce the amount of wind, dust, and other contaminants that may hinder installation.
Applying the Film
You should start with the back of the vehicle, then work your way to the front. This ensures that when you are driving the vehicle, wind will not peel up the graphic.
Trim the film on the car to ensure a proper fit. A printed piece of 60" film works best with transit applications—buses and panel trucks—whereas 48" to 54" films work for passenger vehicle applications. To avoid shrinking of the film or mechanical wear on the open cutting edge, avoid cutting the film flush with car edges. Instead, leave a little extra film during your cut to tuck into and around the edges.
Apply the film with a squeegee, using short swipes that overlap the previous swipe. For rounded surfaces such as fenders and tightly curved panels, work small sections at a time, using a heat gun to evenly heat the film. Move the heat gun constantly to avoid damage to the film. Cut and fold edges only after the film has cooled.
Any deep-drawn areas, borders, and edges should be carefully reheated in order to quickly activate the adhesive. In case of deep corrugations, reheating the area to almost production temperature of the film—approximately 356°F—is recommended. While this may seem very high, it is necessary to achieve the required migration of softeners needed to harden the film. This temperature will not damage the adhesive substance or the vehicle’s paint.
When the wrapping is finished, if necessary, reheat all borders, edges, and corrugations. If you notice tiny air bubbles under the film, don’t panic. They will diffuse through the film within a few days depending on the ambient temperature. Larger bubbles should be punctured by an air release tool and the air pressed out with a squeegee.
Use caution when applying film to unpainted plastic parts such as bumpers or fenders. If in doubt, use the water drop test. If water runs off in drops after the cleaning procedure, it is not advisable to apply film to this surface. In any case, all surfaces should be smooth since films will not typically adhere to a structured surface for long.
Maintenance and Removal
After three days you should be able to take the car through a car wash without problems. Polish shouldn’t be applied to the car for at least three weeks after wrapping. Only wax-free, silicone, or Teflon polishes should be used. If possible, avoid high-pressure cleaning or caustic chemicals.
While high-performance cast films and laminates can maintain adhesion and image quality for up to seven years, most manufacturers recommend that vehicle wraps be removed within three to four years to minimize adhesive residue and interaction with the underlying surface. By that time, you’ll probably be ready to apply a fresh marketing message anyway.
There are a few important items to have when installing a vehicle wrap. Cotton gloves should be worn to avoid fingerprints and for handling heated vinyl. Low-tack masking tape will be needed for positioning the film, as well as a felt-tipped or Teflon squeegee. A sharp hobby knife will be used for trimming away excess vinyl. You will need an air release tool for removing air bubbles, as well as a rivet brush for installation over rivets. Also, a heat gun may be necessary. These tools and tips will help you complete the installation successfully.