Beneath the Surface Blog

Designing with translucent surfaces, structure, and backlighting is a delicate balance– those are three difficult materials to make work together. There are several methods to illuminate glass surfaces with backlighting, and chances are if you're creating a ceiling or wall, then you have little space in which to throw the light. Because glass is a substantially heavy material, throwing cumbersome structural members into the mix further complicates things.

Here's a video example of a prototype that GPI developed for a backlit glass ceiling project. The assembly includes metal standoff hardware, recycled glass panels, colored LED panels, and lighting controls – all customized and calibrated to complement each other, for a seamlessly blended illuminated finish.

Here are our top 3 tips for designing with backlit glass panels:

1. Don't disregard structure. Move the flat LED panels in front of all structural pieces in order to avoid casting shadows.  Glass is often used in conjunction with standoffs or steel angles.  Ensure that the lighting elements can be implemented into your chosen method.

2. All types of glass have different diffusion characteristics. Be sure that your lighting manufacturer can make proper modifications to the lighting fixtures to properly illuminate your chosen glass, or consult a lighting designer that is well-versed in methods to eliminate halos, hot spots, and cold spots. Create a custom mock-up or consult an expert to discuss the optimal dimension between LED panel and glass surface for best light diffusion.

3. Consider specifying a clear or white glass and use the lighting to provide the color. That way, your client can dial in the exact color desired and use different settings for special occasions.

Still struggling? Send us your sketches for design consultation.

Considering highlighting a countertop or reception desk with an illuminated white surface? At a recent project for a custom reception desk, smooth white Corian® surfaces were illuminated by GPI’s custom LED backlighting system. Providing an intriguing focal point, the luminous desk has clean lines and a sleek white appearance that was fitting for the space – a high-end architecture firm.

Here’s what we learned through the process of creating this LED backlit Corian reception desk:

1. Corian® Illumination Series Glacier Ice looks best in commercial spaces when illuminated with lighting temperatures in the cool range. (Pictured below with both our Cool White 5300K and Warm White 3500K LED panels.)

2. The Corian® Illumination Series surfaces have excellent light diffusion characteristics, making them ideal for backlighting applications when the appearance of bulb lines is not desired.

3. Given the thickness and light transmission characteristics of the Corian® surface, there is a delicate balance in the calibration of the lighting cavity to both maintain LED panel brightness and eliminate the appearance of hot spots. To maintain brightness by keeping the LED panels close to the illuminated Corian®, LED strings were buried in the casework to disguise bright lines.

4. Based on many factors, including size of LED panels and desk construction, we calibrated that our Infuse™ LED panels should be situated 1 ¼” away from the back of the Corian® panels.

5. Treatment of corners is especially important in maintaining even illumination – we coordinated closely with the millworkers to ensure that the panels were accurately sized to fit into the desk casework. Even a few millimeters of incorrect sizing and the desk would have gaps between the LED panels – resulting in distracting shadow lines.

A pretty typical situation occurred here at GPI this week.  A lighting design firm had specified our Infuse™ flat LED panels for a large commercial project, and the contractor ended up making a substitution in order to try to save some money.  As it turns out, the substituted LED panel product looks absolutely terrible and the entire team, including the client, is very unhappy.  So, we received a slightly panicked email from the architect and lighting designer asking us to step in and solve the problem. 

We suspect that the substituted product was poorly made, but assuming that it wasn't, there's still a host of problems with the application.  Even if all flat LED panels are created equally, this particular LED company did not pay attention to the details, and ultimately wasted a significant amount of time and money.  The problems? Uneven illumination, panels sized incorrectly, bulky hardware that is interfering with the light, and absolutely no attention to light diffusion strategies... the textbook case for our integrated systems and process.

Budget is indeed a critical issue in building construction.  Flat LED panels are typically used in feature areas of buildings, becoming main spatial focal points that are evaluated with a discriminating eye.  So if you're looking to cut costs, it's not always wise to do so in such high-profile areas. 

The lesson here: investing more money up-front in a system from a company that will perform as you expect will help avoid costly replacements and changes down the line.  Many of our designers, especially our repeat clients, realize this value, but it can be difficult to communicate this seemingly intangible value to their clients.  What strategies do you use to convince building owners to invest in high-end products?

The last post on "Beneath the Surface" discussed some of the challenges that flat LED panels pose when used for backlighting applications.  This post address each point with a design-driven solution. Anything we're missing?  Leave a comment and we will address it with another blog post!

1. Hot spots

Depending on the translucency of the surface being backlit, hot spots along the edges of LED panels are often a major design concern.  You can accommodate this setback by burying the hot spot in structural framing, or increasing the space between the backlit surface and the LED panel to diffuse the hot spot.

2. Difficult to determine how many edges to run LEDs across

This is a tough one- since most LED panels are custom produced to size, it just takes experience and experimentation to know how many edges require light sources.

3. Cold spots

Consider the ideal size of the panels; although many manufacturers can produce flat LED panels in 4’ x 8’ sheets, it can be beneficial to break that module down into smaller panels.  A good rule of thumb is to allow each LED string to throw light 15” – 20” across the face of the panel.  So, if your panel is over 20” wide, consider running strings on two parallel sides. 

4. Expensive

LED panels have higher upfront costs, but can have dramatic energy savings, especially when the LED lighting system is controllable.  By using flat LED panels in applications for which they are best suited (feature areas which require evenly illuminated surfaces and when you have limited space in which to throw light), you can preserve your client’s budget and make the most impact where needed.

5. Imperfections in acrylic batches

Tight quality control standards will ease this challenge.  Unfortunately, designers don’t have much control over this part of the production process, so be sure to choose a manufacturer that you trust and that has strong attention to detail.

6. Powering every single panel with an adapter

Specify a complete LED backlighting system that has power supplies that can run at least 50 linear feet of LED strings.  Running an entire backlit wall or ceiling back to a central power source results in more efficient wiring and installation.

7. Panels have varying brightness

Balance out the brightness among panels by specifying dimming packs that can control each LED string and each panel individually.  If a small panel appears brighter, or a panel closer to natural sunlight appears dimmer, you can control the brightness of the panels via a manual user interface or through a central building management system.

Have you experienced any of the above issues?  How did you design around those product limitations?  Now that you know a bit more about flat LED panels, enjoy designing your next unique backlit feature!

Flat LED panels are new technology, and if you’re a designer or architect you are probably aware of a handful of manufacturers that produce these products.  And while many of the physical characteristics of LED panels are the same across the board, the majority of manufacturers lack the expertise to implement the panels with actual surfaces in actual construction environments. Here are some considerations when specifying flat LED panels for commercial projects:

 1. Hot spots

Edge lit LED panels are manufactured by embedding energy-efficient, high output LEDs along the edges of a thin acrylic panel.  Laser-etched channels distribute light across the face of the panel.  There is often a bright line at the edge of the panel where the actual light source is located.  This bright line can transfer through the surface being backlit, disrupting the visual continuity of the surface.

2. Difficult to determine how many edges to run LEDs across

If engineered incorrectly, too many LED strings will result in bright panels with excessive hot spots at the edges.  Too few LED strings will cause cold spots at the unlit edges and possibly towards the center of the panel.

3. Cold spots

If panels are sized incorrectly or LED strings run on the wrong sides of the panel, the light source may not sufficiently transfer across the entire face of the panel, resulting in cold spots towards the center of the panel.

4. Expensive

The up-front cost of LED technology is expensive, and it can be difficult for architects and interior designers to convince clients to invest in high-end products.

5. Imperfections in acrylic batches

Acrylic production results in slight variations between batches; this is very typical for the acrylic industry, but when you add light to the mix, the imperfections are exaggerated.

6. Powering every single panel with an adapter

Not a problem if you’re designing a backlit bartop for a residence, but when designing large commercial features, plugging each individual panel into an outlet is inefficient (and quite ridiculous, if you ask us!).

7. Varying panel sizes have varying brightness

Depending on the proportion of the panels (long rectangles or even squares), smaller LED panels will appear brighter than larger panels.  This is due to light bouncing in a decreased area, and also because of the voltage drop that occurs over the longer LED strands.

One of the elements of being a great designer is knowing the limitations of the product you’re investing in.  Stay tuned for the next blog article which will outline how to design around the above challenges.

Project Update: LED Light Panels at AED Idea Center Installed, Glass Panels Evenly Backlit

Backlit Glass Columns by GPI | AED Idea Center | Washington, D.C.

Architect: Studio 27 Architecture

Lighting Designer: MCLA

Application: Backlit frosted glass at eight columns

Products: GPI Infuse™ Flat-Lite™ LED Panels at 3500K lighting temperature

Integration: Diffuser films to hide lamp image and disguise hot spots, GPI Infuse™ Custom Power/Dimming Packs that communicate with Lutron 5000 Graphic Eye to balance brightness between large and small panels

This is a rough progress image from the field.  Check back for completed photographs when the dimming interface is completed!

(Blog Update 1/16/11: see the completed photographs)

Project Update: LED Panels Wired and Installed, Glass is Evenly Backlit

Backlit Glass Columns by GPI | AED Idea Center | Washington, D.C.

Architect: Studio 27 Architecture

Lighting Designer: MCLA

Application: Backlit frosted glass at eight columns

Products: Frosted glass panels, GPI LED Panels at 3500 K, GPI Custom Dimming Packs that communicate with Lutron 5000 Graphic Eye

Integration: Diffuser films to hide lamp image and disguise hot spots, GPI Dimming Packs to balance brightness between large and small panels

Above image indicates construction progress from the field.  Check back for completed photographs when the dimming interface and surrounding finishes are complete!

A photo update of our installation progress on-site in Norfolk, Virginia (see the Wells Fargo project rendering for the final vision). Most of the steel has been installed and a few FLAT-Lite™ LED panels were tested.  Everything fit together perfectly and it looks like the columns will be installed tomorrow.


The reception wall (above) had some framing adjustments, which pushed back the column installation.  Steel and LED panels for reception wall will be going up today, translucent stone panels tomorrow.


All of the DURA-Lite™ panels are prepped, mechanical fasteners are aligned and secured, ready for installation.


Framing out the square lobby columns (above) in preparation for hanging our stone panels. 


All of Terry's precise work and attention to detail in the framing systems and it's soon going to be covered up with the stunning Mercury onyx panels! Check back soon for even more progress on the finish surfaces and lighting systems.

2. The orange Mercury onyx that the designers chose for this project is pretty unique (see below photograph of the unlit stone) and is sure to look gorgeous all lit up.  Can’t wait to get those stone photos up on the website!

3. All of the corners are meticulously quirk mitered and have been detailed down the the millimeter, so the vertical reveals are a clean architectural detail.

4. The tolerances on our products are pretty low, so the size of all the stone panels, LED panels, trims, and fasteners have also been detailed down to the mm before production.

5. We’ve gone to great lengths to make sure the book matched  seams are perfect.  So we’ve been harping on our stone guys to make the perfect cuts and account for stone waste.

6. Every single component will arrive on site at the same time; stone, LED panels, wiring, all of our tools, our crews, even stainless steel trims.  That’s a whole lot of coordination!

7. This marks the second large commercial job which will be using our NEWLY engineered increased capacity FLAT-Lite™ power supplies with integrated dimming capability.  So full dimming control can be achieved through the Lutron BMS, and can be set for each individual interior lighting scene!

After months of coordinating between the general contractor, electrical subcontractor, millwork subs, and owner to make sure everything goes smoothly, tomorrow the ball drops – check in daily for updates on the construction process.

Thanks to all those who behaved themselves on St. Patrick’s day to prepare for the trip to Norfolk!

View the Wells Fargo Center project rendering

Our design team is continuously building our materials library with the latest and greatest in architectural surfaces. Backlighting translucent surfaces is what we do best- especially if you're crunched for space and need even illumination across a surface. Based on the properties of the surface you choose, we'll provide consultation for lighting systems and construction details to achieve your intended lighting effect.

GPI International can provide backlighting for virtually any translucent surface you can dream up. Here's just a sampling of recent products we've been integrating with our FLAT-Lite™ LED panels:

• Glass (recycled, printed, frosted)
• Resin / plastic / acrylic / polycarbonate / PETG
• Stretch fabrics
• Translucent honeycomb panels
• Screens

Interior designers, architects, spec. writers, contractors - what new products are you itching to use but haven't found the right application for yet?