Whether it's spring, summer, winter or fall, there are vinyl signs outside battling the elements. The main obstacle to outdoor durability is UV radiation from the sun. Choosing the right vinyl is the first step to making sure that whatever comes out of your Vinyl cutter stands the test of time. But in order to choose the right vinyl for the job, you need to understand how the sun impacts your work and what a vinyl film's outdoor durability rating really means.
To meet or exceed customer expectations, you must choose the right vinyl, understand the details of the makers’ warranty, know the difference between the durability of printed vinyl vs “cut vinyl”, and be aware of environmental and maintenance issues. Let’s tackle these in that order.
Choose the Right Vinyl for Your Vinyl Signs
By now you probably know there are major differences in the outdoor durability of various self adhesive vinyl films. In previous blog posts, we’ve discussed the virtues of cast and calendared films, solvent and acrylic adhesives, and looked at various types of vinyls like reflective film. To categorize them in terms of outdoor durability, it might help to break them into four groups.
- Calendared PVC: These are the economy and intermediate vinyls used for short to medium term outdoor vinyl signs and graphics. These include EnduraGLOSS, EnduraMATTE, ORACAL 631, 641, and 651. They tend to have outdoor durabilities ranging from three to six years depending on the color. Metallic colors like silver and gold will fade more quickly because of the metal flake content. We’ll explain that momentarily. Standard colors are more durable with reds on the lower end of the range. The most durable options in any vinyl product palette are typically black, white, and transparent. No matter what color you choose, the projected outdoor life assumes a vertical application in an environment relatively free of chemicals and pollutants. More on those later.
- Cast PVC: These are the higher-performance versions of their more affordable counterparts. The primary difference between cast and calendared PVC vinyl is the superior dimensional stability produced by the casting process. This gives cast films outdoor life ranging from five to twelve years depending on the brand and type. Why such a broad range? One factor is the amount of UV inhibitors baked in during the casting process. ORACAL 951 has more UV resistance than 751, its more affordable alternative, and lasts up to 25% longer outdoors. Remember that not all cast vinyl is standard PVC film. There are also cast metallic and ultrametallic films used primarily for automotive accents. These have shorter outdoor lives because the metal flake in the pigment traps and holds more heat resulting in a shorter road to failure. Metallic and ultrametallic cast films tend to expire in three to seven years depending on the color. Metalized polyester films are even more susceptible to heat failure and should be put in their own category.
- Metalized Polyester: Metalized polyester, or mylar films, are used to emulate dazzling metallic effects and textures such as brushed and smooth chrome, gold leaf, and holographic foils. Instead of bits of metal mixed into the face stock, these films contain a layer of metallic foil. Typically, metalized films like silver and gold chrome mirror are only good for up to two years outdoors. Some expire in as little as six months as the accumulated heat causes them to blacken like tarnished silverware. There have been advances in the last five years in this field so you can now purchase metalized films that last three to five years outdoors. Our VC series Schein holographics are in that category. Beware. Some brands are available in both a long term or “durable” version and a short term or “decorative” version. Don’t use decorative foils for long term outdoor signage unless you sell them only to people you don’t like.
- Fluorescent: Despite the fact that fluorescent vinyl is either cast or calendared PVC, it deserves to be placed in its own category in this discussion. As noted above, not all pigments are as durable as others. Fluorescent pigments are at the bottom of the UV toughness list. Regardless of whether it’s a cast or calendared film, fluorescent vinyls are inherently limited to short term applications. Depending on the hue, some may last up to two or three years. But fluorescent reds and yellows are notoriously susceptible to dramatic UV fade. Use these only for short term promotional graphics such as “going out of business” sales, retail promotions, or indoor graphics. If your customer insists on a fluorescent green for his or her signage, do your best to persuade them to opt for a similar color in a more durable product. EnduraGLOSS # 521 Lime Green, and ORACAL’s #063 Lime Tree Green for example, are popular and durable substitutes for fluorescent green.
Climate Zones and Horizontal Application
The Features and Benefits document for ORACAL 651presents the product as a "6-year intermediate calendered" vinyl. But does that mean that any graphic made with ORACAL 651 will last for six years or more outdoors. Simply put, no. It depends on how and where you install the graphic, and on what kind of substrate. As page 3 of the Oracal General Warranty states, the 'where' is a big factor. There are three different climate zones identified in the warranty. This is because the main enemy of vinyl durability is UV radiation from the sun. And, as we all know, the sun's rays hit certain parts of the planet harder than others. Therefore, the actual warranty depends on what zone your sign, banner, or vehicle graphic lives in.
Signs installed in Climate Zone 1 enjoy the full six year warranty. Climate Two graphics are subjected to more intense UV rays and are warranted for a full year less. only five years outdoors. Signs made with 651 in Climate Zone 3* signs have an outdoor life expectancy of four years; fully 33% less than the standard warranty statement. So, when you're delivering a finished vinyl graphic and setting customer's expectations about durability, be mindful of your climate zone.
But looking at the Climate Zone 2 chart at left, there's obviously another factor at play. There are two columns, labeled Vertical and Horizontal. This adds another critical factor in the outdoor durability equation. And it too, is based on UV exposure. Horizontal exposure - applying a vinyl graphic on a plane perpendicular to the noon-day sun - will cut it's outdoor life in half. That begs the question, what constitutes a 'horizontal' installation? It's not vehicle hoods and awnings. The fine print on page three states "Applications with a deviation from the vertical level of more than +/-10° are considered horizontal applications." . 90° is vertical. Anything at an angle of 80° or less is considered horizontal and only gets half the expected outdoor life and warranty coverage. This includes graphics installed on most automotive windshields. So, if you're selling a vehicle graphics job that includes vinyl on the windshield, and your customer wants it to last five years, they'll need to use a ten-year vinyl. Choose your vinyl and set your customers' expectations accordingly.
So never tell a client that this is how long your sign will last. We recommend inserting the words "up to" before you quote the film life. There's a big difference between laboratory life and real world life. Be aware of the detrimental affect of the sun’s rays on vinyl installed horizontally or at an angle, and set your customer’s expectations accordingly.
Outdoor Durability of Printing Ink on Vinyl
As sign makers have moved from using vinyl primarily in plotters to using it as a digital printing medium, there has been some confusion about the predicted outdoor life of a printed vinyl graphic. ORAJET 3951RA for example, is rated for ten years outdoors and is suitable for use with Mutoh Eco Ultra, MS41, and EnduraINK PRO ink.
That does not mean that an image printed with this ink on 3951 will last for ten years without fading. What it means is that the vinyl will last for ten years before it begins to shrink, crack, yellow, or peel. Solvent and eco solvent inks are generally rated for up to three to five years outdoors. By the time the 3951 reaches the end of its usefulness, the ink will have been erased by the sun. Don’t promise your customers that your prints will last seven to ten years just because they’re printed on high performance vinyl. If you make that mistake, your reputation will fade along with your prints. Remember the word "up to".
Speaking of printing and vinyl, this takes us back to step one. Choose the right vinyl. Plotter films like ORACAL 651 and EnduraGLOSS are not designed for inkjet printing. They may look okay if you run them through your large format eco-solvent printer, but the surface treatments used to produce the desired levels of gloss on these products will deter the ink’s ability to penetrate the surface. The result will be inferior abrasion and UV resistance. If you want to get the most out of your printer, use solvent printable vinyl. The roll cost may be higher, but the square foot cost will be within pennies of the plotter film and your prints will perform as expected.
Environmental Factors Affect Your VInyl Signs
Finally, let’s consider the environment factors that affect outdoor durability. By environmental factors, we mean known chemicals or pollutants.
Pollutants: There is a problem that has arisen in Southern California, Arizona and parts in between. Wrapped vehicles in these areas often fail due to something called “acid dew”. Corrosive pollutants in the air condense in the dew and collect on wrapped vehicles. As the dew evaporates, the pollutants are left behind and leave a rusty, crusty coating that erodes the overlaminate. If you’re installing vinyl graphics in this region, you would be wise to follow these steps from the ORACAL Dealing with Fallout Bulletin.
Suggestions for Sign Shops:
- Prepare a Vehicle Wrap Care Guide
- Educate Wrap owners of the importance of care
- Modify warranties with regards to fallout to avoid liability issues.
- Always use the words "up to this many years" when discussing the length of outdoor durability because you don't know how the customer is going to treat the letters/decal you provide.
Suggestions for Vehicle Wrap Owners in this area:
- Rinse the vehicle every morning to minimize deposits
- Wash the vehicle at least once a week with a very mild soap. Ask wrap installers for a vehicle wrap care guide.
- Use a Teflon type polish designed for vehicle wraps to help protect the surface and gloss. Follow manufacturer’s directions and application frequencies.
As technology advances, the quality of the materials used in digital sign making gets better and better. Ten years ago, cast vinyl was only expected to last 8 years outdoors, and calendared films were only good for half that lifespan.
Now you can install and warrant your vinyl signs and graphics for up to 12 years. But there are important distinctions and limitations. Knowing these and educating your sales people, installers, and customers, can make the difference between managing a growing business and struggling to stay afloat.
To keep your business growing, remember to choose the right vinyl for the job, understand the difference between the life of a printed image and its substrate, and be aware of environmental issues that can degrade the life of your product.
*Zone 3 includes South Hawaii, South Florida, Mexico, Central America and many South American nations.