For an internally illuminated SEG light box, buy the LEDs, driver and graphic as a matched system. Frame depth, fabric transmission, optical layout and wiring determine the result. An external arm light can illuminate a fabric frame from the front, but it does not turn it into an internally lit lightbox.
What SEG describes
SEG means Silicone Edge Graphics: printed fabric with an edge strip that fits into the frame groove. The edge treatment does not specify the lighting. Confirm whether the frame is unlit, front-lit or designed for internal illumination, and use fabric intended for the selected method.
Choose the lighting layout first
| Layout | How it works | What to check |
|---|---|---|
| Internal edge lighting | Modules at the frame edges direct light inward behind the graphic | Optical orientation, distance across the graphic, depth, opposing edges and reflective surfaces |
| Internal direct backlighting | LEDs behind the graphic face toward the fabric | LED-to-fabric distance, array spacing, diffusion and visible bright points |
| External front lighting | Arm lights or suitable spots illuminate the outside face | Mounting fit, beam overlap, top-to-bottom brightness, reflections and visitor glare |
Internal edge lighting and direct backlighting both illuminate from behind the fabric, but their module placement and optics differ. Neither automatically guarantees uniform light. Compare the complete system cost, access for repairs and transport needs rather than assuming one method is always cheaper.
Measure before requesting a quote
- Graphic width and height; one or two illuminated faces.
- Clear internal frame depth and space for modules, cables and the driver.
- Profile cross-section, mounting positions and obstructions.
- Final printed backlit fabric, backing and reflective surfaces.
- Target appearance under the intended venue lighting.
- Required plug, supply, cable route, control and service access.
For edge lighting, frame depth and the distance the light travels across the graphic are separate measurements. A quoted reach across a panel is not the minimum frame depth.
Check actual module specifications
The current 12W/18W module for compatible MODULAP fabric lightboxes provides a useful comparison:
| Specification | 12W | 18W |
|---|---|---|
| Listed output per module | 1320lm | 1980lm |
| Input | DC24V | DC24V |
| Dimensions, including lens | 470 × 23 × 16mm | 470 × 23 × 16mm |
| Listed lens | 9° × 50° | 9° × 50° |
Both use a 2-pin plug-in connection. Check the actual mating connector, polarity, cable direction and screw locations. The 16mm dimension includes the lens; it is not the aluminum thickness. Higher output does not establish suitable spacing or eliminate a dark center.
Plan the complete electrical load
This module requires an external DC24V constant-voltage driver, which is not included. Six 12W modules have a nominal load of 72W, or 3A at 24V. This calculation is not permission to use any 72W driver: allow the driver manufacturer's design margin and verify its operating conditions, branch wiring, connectors and voltage drop.
Confirm the specific dimming method. This module's listed control reduces brightness to approximately 50%; below that point it switches off. Do not promise a 0–100% dimming range.
Approve a sample with the finished graphic
- Build the planned depth and LED positions with the intended backing.
- Fit the final printed fabric, rather than judging the bare LEDs.
- Inspect center, edges, corners and bright points under expected ambient light.
- Adjust spacing or placement, then recheck the whole graphic.
- Run the sample until its temperature stabilizes within the component instructions; check wiring, mounting and maintenance access.
Select color temperature by testing the printed whites and colors. CRI describes comparison with a reference source, not a guarantee of every brand color; see the NIST explanation. Record the approved model, color option, layout and electrical plan for repeat orders.
When external lighting is appropriate
For a fabric frame that does not require internal illumination, external lights can be a practical option after testing coverage. Confirm both ends of the mounting connection and check the full graphic. A fixed rule such as one lamp per metre ignores height, distance, optics and ambient light.
Use the mounting guide and booth-light buying guide. For an internal build, compare LED lightbox modules using the measured frame and tested layout.