Whether it’s summer, spring, winter or fall, there are signs outside battling the elements.
One of the common hurdles to outdoor durability is pollution but the main obstacle to is UV radiation from the sun.
It is also important to note that the lifespan of the design can vary depending on the colours chosen. Not all pigments are created equally and some are more inherently susceptible to UV fading. For example, metallic colours like gold and silver often fade more quickly because of the metal flake content.
So when helping customers pick colours for their designs, remember that standard colours are more durable with reds on the lower end of the range.
If you’re printing on vinyl, the most durable tones are typically black, white and transparent.
Why UV [ultraviolet light] causes colour to fade
Because of photodegradation.
In layman terms, there are light absorbing colour bodies that are present in dyes and the colour(s) we see are based upon these chemical bonds and the amount of light that is absorbed in a particular wavelength.
UV rays can break down the chemical bonds and fade the colours in an object – it is a bleaching effect.
What about fluorescents?
Despite their allure, fluorescent pigments should only be used for short term promotional graphics such as ‘going out of business’ sales or time sensitive retail promotions. The reason being is that fluorescent pigments are at the bottom of the UV toughness list – depending on the hue some may last up to two to three years but fluorescent reds and yellows are very susceptible to dramatic UV fade.
TIP: If your customer is adamant on fluorescent green for his or her signage do your best to persuade them to opt for a similar, non-fluorescent option.
Reducing the amount of sun exposure when hanging or mounting a sign is also wise because non-vertical signs get more UV exposure than signs hung at a perfect 90 degree angle.
Just like human skin needs protection from the sun on a sunny day, signs benefit from being printed with inks that are resistant to UV rays. UV inks are waterproof as well as fade resistant and should be chosen over water-based inks for outdoor signs that will stand outside for more than a day.
Pros and Cons of Vinyl
One of the main advantages of a sign made with vinyl is longevity.
While the sun can eventually start to fade it, you can expect a vinyl sign to last 5-10 years or more.
One of the disadvantages is that vinyl doesn’t offer the same print colour-specific options or the fades that are printed copy’s advantages.
The trade-off however is two part because digitally printed signs will not last as long as vinyl signs. Whereas vinyl signage should last 5+ years, digitally printed signs tend to last about 3 years.
TIP: If a digitally printed sign is what your client is after, consider laminating the sign because it can add an additional 2-3 years to its life expectancy.
Lastly, printed signs are more susceptible to scratches (again this can be lessened
with lamination). This really isn’t a problem with vinyl.
If you have any signage questions or queries don’t hesitate to contact us and one of our friendly experts will get back to you.
Michael T. Lauer, DxO Optics, Lightroom, Photoshop