This will somewhat depend on your outdoor signage, but in reality, most materials, printed, painted or constructed in the 21st century will last about the same amount of time with or without lamination or clear-coating.
Some sign gurus, though, might disagree with me in some instances, so I'm going to tell you what and why that might be the case, and why we do sometimes and why we don't most of the time.
Adding an Over-Laminate
We often do add a clear matte over-laminate to digitally printed decals because clients think they're getting something extra, and the cost is not too high to do so, and when we let them know we're throwing it in for free, our clients love it. However, most digitally printed inks today will do quite well in sunlight, and clear laminates are NOT sunscreens and will NOT help a decal to keep from fading.
What lamination is for is mostly a protectant against abrasion prevention. If, for instance, a sticker or decal will be used in an area where it may be brushed up against, such as on the side of an escalator or elevator, an over-laminate will prevent ink from rubbing off earlier than normal. Another reason for protection is for keypad decals that get a LOT of usage, but rather than using a laminate, polycarbonate decal material, usually 10 or 15 mils in thickness, is printed second surface and then an adhesive is laminated behind the ink, creating a durable subsurface printed decal that can handle a lot of contact over time, such as on a calculator or a kitchen appliance.
For Dimensional Signs
For signs that are dimensional, such as a sandblasted cedar, redwood, or high density urethane sign, the only reason I see for a clear coat might be graffiti clean-up if the sign is vandalized. It used to be the case, when signs were hand-painted on MDO plywood or other substrates, and sign painters used oil-based enamel paints, they would often clear-coat the signs to prevent "chalking off." This happens as paint ages and it gets a kind of powdery white coating that "grows" on the surface of the paint. To prevent this, a clear-coat was often added to the painted signs that helped them not to chalk off and remain bright and readable for a longer period of time. This would be similar to why a car manufacturer will apply a clear coat or two over the finish paint on an automobile. It keeps the paint looking good for a couple or three additional years.
Why Put Laminate On
The only other reason I can think of to clear coat or use a clear laminate on any signs or stickers or banners would be to make the entire surface either matte, semi-gloss, or glossy. Sometimes when you print a substrate such as a vinyl decal material, the ink may have variations in the glossiness due to the flat finish of the decal material. In this case, using a matte or gloss over-laminate will help to even out the look of the decal or whatever else you printed.
However, for the most part, the myth of longevity is over-rated. Clear-coating and lamination may assist in some improvements as shown above, or in achieving a uniform look to your sign, banner, or decal, but preventing fading or increasing the life of a sign or sticker - not so much.
Click here to see durable laminated display lettering sign.
ABOUT THE AUTHOR
Barry K. Brown has been in the Sign, Banner, Decal and Display Business for over 20 years. It isn't what he thought he'd do with his life, but he says he knows too much now to do anything else!
He has been marketing these products online since 1998, and the company he was general manager of in 1998 was the first sign company to be listed on Yahoo!
He invites you to visit and view his videos on different graphic print banners, decals, stickers, labels, signs, and trade displays.
