GPI International Blog: Beneath the Surface

For many, the word “onyx” evokes images of shiny black beads embedded in jewelry.  Yet as interesting as light-up gemstone necklaces sound, GPI Design creates features with a different sort of onyx, a sort of “jewelry for your walls”.  The world of onyx natural stone is a large one, filled with many colors, banding, and stone patterns.  Many people aren't aware of the enormous amount of onyx varieties available, so we're opening up our image library of slabs to set your imaginations running wild.

What exactly is onyx? In the commercial stone world, onyx is not a color or specific stone, it encompasses a broad range of stones. Onyx is a form of quartz.  Quartz is the second most abundant mineral in Earth’s crust and comes in many different varieties, one of which is onyx.  But wait a minute, you might be asking: “isn’t quartz the stone that comes in large crystals?”.  Yes, those large chunks of crystal are known as macrocrystalline quartz.  The other major category of quartz is microcrystalline (or cryptocrystalline).  

Onyx is a form of cryptocrystalline quartz, which means that is composed of large bunches of much smaller quartz crystals. It’s the combination of tens of thousands of smaller quartz crystals that give onyx its huge variety of colors, textures, and patterns.  If you look closely at a slab of onyx, you can start to see the individual crystals that make it up. Particularly when backlit, the fine detail in an onyx panel is further revealed. 

Green Onyx- Rich layers of green are enhanced by billowing clouds of red and brown.  Green onyx has a luxurious, rich look, and is often used to create a sense of magnificence and warmth. Backlighting green onyx panels brings out hidden details and adds an additional layer of richness to the stone.

Now that you know the world is your oyster when it comes to designing with backlit onyx, unleash your most colorful imagination! Stay tuned for our next featured stone.

One of the most popular acronyms in the lighting design world and in the lighting section of GPI Design is LED.  So what does it stand for, and how do LEDs work?  While not an exhaustive investigation, this blog post will give you a primer on LED lighting technology and how LEDs work.

An LED, or Light Emitting Diode, is a semiconductor light source.  When an electrical current flows through the diode, electrons in the current experience an energy drop.  During this drop, energy is released in the form of light.  LEDs emit different colors due to different energy drops or due to a coating on the LED. That’s how GPI can offer different lighting solutions with colors like white, red, blue, yellow, and more.  LEDs are extremely efficient, last longer than traditional light sources, and are capable of producing clearer, crisper light.  LEDs are gradually replacing older forms of lighting, including incadescent bulbs and florescent bulbs, and are quickly becoming the light of the future.

So how exactly does an LED work?

1. An LED is hooked up to an energy source.

2. An electrical current flows from the positive terminal, through the diode, and out the negative terminal.

3. An electrical current is composed of electrons.  The electrons, when flowing through the diode, drop down to a lower energy state.

4. During the drop, energy is released in the form of photons, or small packets of light.

5. The light bounces around in the plastic shell of the LED, and then escapes as visible light.

An LED gets its energy from a low, constant DC voltage.  An individual LED requires 2-4V of DC power and several hundred mA of current. LEDs connected in series as part of an array require higher voltage.  In order to get the correct DC voltage, LEDs require drivers, which convert incoming AC power to the proper DC voltage and regulate the current.  Thus, a driver is considered the power supply of LEDs.  To control LEDs and achieve affects like dimming or color changing, different controllers are used.

While it seems like there are many parts to LED systems- drivers, controllers, bulbs, panels, scrims- our Infuse™ System brings them all together to achieve beautiful backlit features with complete LED backlighting systems.

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.

As an integrated engineering, design, and supply firm, we frequently work with suppliers, engineers, designers, and architects to provide our unique backlit onyx features. One topic that seems to be shrouded in mystery is the topic of fire safety and fire requirements. Terms are frequently confused or misused, and data is often difficult to find (if it even exists). So what are the different areas of fire safety?  What guidelines or codes do you have to follow?

First off, every country, and sometimes even city, has its own building codes that specify certain safety requirements in structures.  In the U.S., the most frequently used code is the IBC, (International Building Code) which is put forth by the ICC (International Code Council).

To meet these requirements, certain standards and tests must be carried out.  To this end, technical standards are written that dictate a list of requirements that must be met. These technical standards, or specifications, can be written by private companies, government agencies, or standards organizations- ASTM, ISO, CEN, etc.

Those are the basic terms, for those unacquainted with building codes and standards.  Onward to the flames!  There are two major categories of fire safety ratings.  First there is fire resistance.  Fire resistance deals with the ability of structural components (walls, floors, ceilings, doors) to restrict the spread of flame and maintain structural integrity in a fire. Fire resistance relates to structural fire performance and becomes important after a fire has started and threatens a building's structural integrity.  The fire resistance test method used throughout the United States is ASTM E 119, Standard Test Methods for Fire Tests of Building Construction and Materials.  Fire resistance is usually measured in hours that the material or structure withstands the flame of a certain temperature.

However, not everything in a building must be tested for fire resistance. Interior finishes and exposed materials- wall coverings, ceiling finishes, etc.- are usually tested for flame resistance.  Flame resistance deals with the potential for fire growth within a structure.  Instead of fire resistance, which describes the performance of materials once a fire has already started, flame resistance measures properties in the early stages of a fire. There are several categories within flame resistance; most notably flame spread index and smoke-developed index.

The flame spread index (FSI) measures how quickly a flame propagates, or moves, across a surface. Materials are assigned values in the U.S. using a test known as ASTM E-84, Standard Test Method for Surface Burning Characteristics of Building Materials. Materials are measured on a scale of 0-1000. A low FSI indicates a low burn rate.  Thus, 0 is calibrated to noncombustible materials (i.e. concrete) while 100 is calibrated to 23/32” red oak flooring.  Classification in codes are:



The smoke-developed index (SDI) measures the concentration of smoke given off as a material burns. The index ranges from 0-450, and a low SDI indicates a low smoke development rate.  



Depending on the local codes, building occupancy, and intended building use, different requirements and levels of performance will be needed.  And here at GPI Design, our team of designers, engineers, and architects will work with you to achieve a beautiful LED backlit onyx feature that will meet the codes- and exceed your expectations!