Monthly Archives: January 2013

How to Make Backlit Signs Look Good Day and Night

Posted by Kim Dudley on Thu, Feb 23, 2012 @ 04:28 PM
backlit sample sign spokane
Driving around Spokane, you may not see a whole lot of full color backlit signs.  That’s because full color outdoor backlit signs present a special challenge: constantly changing ambient light.

In the beginning of sign making, backlit signs were hand painted with translucent paint that looked great when lit from the front by the sun as well as at night when lit from behind.  The transition from hand-painting to cut vinyl made the process easier, and translucent vinyl worked well for both day and night settings.  The downside to the vinyl was that it was and still is very expensive compared to other options.  In addition to a high price tag, the vinyl could only produce spot color, so images and text had to be simple. Photos, gradients and special effects were not possible.

Digital printing has solved both of these problems, but naturally, it leads to some of its own complications.  Digitally printing a sign face is more cost effective than either hand-painting or ordering and cutting several colors of translucent vinyl.  It also allows for a multitude of nearly unlimited color choices, and gradients produce a realistic, vibrant image.  The complication arises when different lighting – from the outside by the sun, and from the inside by electrical lighting – hits the print.  If the sign looks good in daylight, the backlighting will completely wash out the color at night (see the far right image, above).  For the same reason, if we increase the saturation to make a sign look bright and clear at night, it will be too dark for daytime viewing.

The solution?  After much testing – we found that the best solution was two layers of ink with a separating layer of white ink, all printed on the front side of the sign face.  By printing color, then white, then color again, (triple strike) you get an image that looks good no matter what the lighting.  When the sun shines on the sign, the front layer of ink is all that is seen.  When the sign is backlit, the second layer of color, hidden behind the white ink is pushed through so the sign isn’t washed out.

In the picture above, we printed the same image using three different processes.  The image on the right shows a “single strike,” or just one layer of ink.  This type of printing is great for most signs, but as you can see, the backlighting washes out the image at night.  The image on the left shows the same image printed on the front of the sign face, then printed in reverse on the back side.  This “double strike” method gives better color, but can be very difficult to register exactly on both sides.  The center image is a “triple strike” with color, white ink, then color printed on the sign face.  Our test image is printed with 100% opacity white ink, but by lowering the opacity to 50%, the image is bright and clear, but not too dark.

Even with the extra ink and extra printing time required for a triple strike, this is still the most cost effective option for vibrant full color backlit signs that look great in any lighting conditions.  The color will be sure to last at least 3-5 years, and if the sign is laminated, you can expect 5-7 years of life.

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Signs for Success – Custom Wraps and Graphics is located in Spokane, WA and services Spokane Valley, Liberty Lake, Airway Heights, Cheney and Deer Park, pointing coast to coast wherever successful signs are needed.

Here’s a very good article on using that laminator and finishing in general.

Finishing Touches


You’ve invested in high-end, wide-format post-press equipment. But one thought keeps nagging at you. Are you making the best use of that investment?

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