BlogSigns & Engraving13 Sep 20268 min read
LED Signboards Explained: What Per-Letter Shadow Lighting Is
Halo-lit, reverse channel, 3D lumineux, caisson lumineux. All the names for lit signboards, what each one really means, and what per-letter lighting costs.
LED backlit signboards work by hiding the light behind the letter instead of inside it or in front of it. The letter is solid and opaque. It stands off the wall on small spacers, an LED strip sits in that gap facing the wall, and the light spills out around the edge of the letter as a halo. You never see the LED itself. You see the glow it throws. That is how LED backlit signs work, and the version we build most at NestX in Bamenda is per-letter shadow lighting, where every single letter carries its own light behind it.
Every name for the same thing
This is the most confusing product we sell, because five different names are in use and the people using them do not always mean the same thing. Here is the plain translation.
| Name you will hear | What it actually means | Same as shadow lighting? |
|---|---|---|
| Halo-lit | Light escapes around the edge of the letter and paints a halo on the wall | Yes |
| Reverse channel letters | The trade term. The letter is a shallow box turned backwards so the open side faces the wall | Yes |
| Backlit letters | Loose term. Usually means halo-lit, sometimes means a glowing face | Usually |
| 3D lumineux | French for raised lit letters. What most Douala and Yaounde shops advertise | Usually |
| Caisson lumineux | A light box. A sealed box with lights inside and a printed face that glows all over | No, different product |
| Shadow lighting, per letter | What we call it. Each letter has its own light, its own halo, its own wiring run | This is it |
The one to watch is caisson lumineux. A light box is a perfectly good product, but it is a box. The whole face glows evenly and the logo is printed on it. A halo-lit signboard is the opposite: the letters stay dark and the wall behind them glows. If you ask for one and get quoted the other, the look at night will not be what you pictured.
The three ways we light a signboard
They are not variations of one product. They are three products at three prices.
| Method | What you see at night | Price |
|---|---|---|
| Single light source behind one piece | One soft glow behind the whole plaque or logo panel | 60 000 - 80 000 XAF |
| Per-letter shadow lighting | Each letter floats in its own halo, dark letter, bright outline | 80 000 - 100 000 XAF |
| Large lit signboard, per-letter lighting | Full shopfront name, every letter lit separately | from 100 000 XAF |
| Light box, printed glowing face | Even glow across a whole panel | Quote in 24 hours |
Single light source is the budget route. It looks good on a round logo plaque in a reception. It looks weak on a long shopfront name, because one light cannot reach the far letters evenly and you end up with a bright middle and dim ends. If your name is long, per-letter is not a luxury. It is the only way it will look right.
How we actually build one
We cut the letters from acrylic, because acrylic is the only common sheet material that carries light properly and does not drink water. We cut up to 1 m by 0.9 m in a single piece. Anything larger is cut in sections that are designed to join, so the seam lands where nobody looks at it rather than through the middle of a letter.
Each letter then gets spacers on the back, which is what holds it off the wall and creates the gap the light lives in. The LED strip goes into that gap facing backwards. Wiring runs from letter to letter behind the letters, into one channel, down to one driver, into one socket you can switch.
Two details decide whether the signboard still looks good next year. The first is the size of the gap. Too tight and the halo is a thin hard line. Too deep and the glow washes out and the letters look like they are floating away from the wall. The second is the wall itself. A halo is light landing on your wall, so a stained, patchy or dark wall gives you a stained, patchy or dark halo. We will tell you if the wall needs painting first. It usually does.
Power draw and what it costs to run
A lit signboard is closer to a light bulb than to a fridge or a freezer. LED strip is the lowest-draw lighting you can buy, and a signboard runs the strip, not a heater. Nobody has ever come back to us saying the signboard changed their ENEO bill in a way they could feel. The letter count matters more than anything else: eighteen letters draw more than seven, because eighteen letters is eighteen runs of strip.
The real ENEO problem is not consumption. It is what happens on the way back.
- The surge when power returns. Cuts do not damage LEDs. The spike when the supply comes back damages the driver. A driver is a small part. Replacing one is cheap, and fitting a surge protector on that circuit at the start is cheaper still. We always recommend it, and we always say so in the quote.
- Half power and brownouts. A signboard sitting on a weak supply flickers, and flickering shortens the life of the driver. That is why we wire lit signboards to a socket with a switch. If the power is behaving badly, switch the signboard off and bring it back when the supply steadies.
- Generator and inverter. A signboard draws little enough that most shop inverters carry it without complaint. Tell us at quote stage if it will run from an inverter, because it changes how we specify the driver.
- Rain. Outdoors, the housing has to be sealed and it has to have a drip path so water that does get in comes straight out again. This is not an optional extra. If an outdoor lit quote looks unusually cheap, sealing is what was removed.
Is per-letter worth the extra?
Per-letter shadow lighting is the one people photograph at night and put on their status. That is what you are buying. A single-source plaque is a nice signboard. A per-letter shopfront is advertising that works from the other side of the road after dark.
Where it is not worth it: small indoor logos under two feet wide, anywhere already washed in bright light, and anywhere behind glass that reflects. Where it is worth it: shopfronts, pharmacies, hotels, bars, bank agencies, and any business whose customers arrive in the evening. The full breakdown of what moves a signboard price is in how much a signboard costs in Cameroon.
For comparison, an illuminated 3D and 2D signboard is advertised in Douala at 250 000 XAF. Our large per-letter work starts at 100 000 XAF. We are not cheaper because the LEDs are worse. We are cheaper because we are in Bamenda and we cut our own letters.
What to send us
We work from PDF, AI, SVG, DXF or CDR. A real vector file means we cut straight from your artwork with no redrawing. A screenshot from Facebook means somebody redraws your logo first, and that is time you pay for.
- The width of the space, in centimetres, and the height.
- One daylight photo of the wall, taken far enough back to see the whole front.
- Your logo file, the original from the designer.
- Whether it is indoors or outdoors.
- Your exact wording, letter for letter, including any small line underneath.
Material choice sits underneath all of this, and acrylic is the only sensible answer for a lit signboard. The reasoning is in acrylic, PVC or wood. Finished lit work is in the gallery, and the published figures are on the signboard price page.
Send the photo and your wording on WhatsApp and we will tell you which lighting method suits the space, then quote inside 24 hours. Everything we make is listed on the services page.
Questions people ask
How do LED backlit signs work?
The letter is solid and sits on spacers a short distance off the wall. An LED strip hides in that gap facing backwards. The light lands on the wall and escapes around the edge of the letter as a halo. You see the glow, never the LED.
What is the difference between shadow lighting and a caisson lumineux?
Shadow lighting leaves the letters dark and lights the wall behind them. A caisson lumineux is a light box: a sealed box with lights inside and a printed face that glows evenly all over. Two different looks at night. Ask for the one you actually want.
What does per-letter lighting cost?
80 000 to 100 000 XAF for per-letter shadow lighting, and from 100 000 XAF for a large shopfront signboard with per-letter lighting. A single light source behind one piece is 60 000 to 80 000 XAF.
Will a lit signboard raise my ENEO bill?
Not in a way you will notice. LED strip draws very little. The real ENEO risk is the surge when power comes back, which damages the driver. Fit a surge protector on that circuit and wire the signboard to a socket you can switch off.
How big can you make it in one piece?
We cut up to 1 m by 0.9 m in a single piece. Larger signboards are cut in sections designed to join, with the seams placed where they are not noticed.
Does my wall need to be painted first?
Often yes. A halo is light landing on your wall, so a patchy or stained wall gives a patchy halo. Send a daylight photo and we will tell you before we quote, not after we install.