Sidelight Modules & Bars — Slim Signage Lighting Guide
Sidelight (edge-lit) modules and bars are designed to light signs from the sides inward, making them perfect for ultra-slim lightboxes, fabric displays, and frameless signage.
This guide covers:
- What sidelight systems are
- Module vs bar format
- Mounting directions and spacing
- Optical lensing and depth
- Power and planning advice
💡 What Are Sidelight Systems?
Sidelight systems are installed on the edges of the sign frame, projecting light across the surface rather than from behind.
They use:
- High-powered, narrow-beam LEDs
- Special lenses to throw light 500–1500mm
- Edge reflection and diffusion (especially in fabric systems)
🔠 Types of Sidelight Products
| Type | Description | Best For |
|---|---|---|
| Sidelight Modules | Compact edge-mounted clusters | Slim lightboxes <80mm |
| Sidelight Bars | Rigid or extruded bar with LED array | Large-format fabric boxes |
| Linear Edge Bars | Even spacing along aluminum bars | Retail stretch frames |
| Asymmetric Lens Modules | Long-throw beam shaping | Wide signs from short edges |
🔭 Beam Angles & Optical Design
Sidelight products rely heavily on optical lenses to spread light across the surface evenly.
| Lens Angle / Type | Use Case |
|---|---|
| 10–15° Narrow Beam | Long throw from frame edge |
| 30° Elliptical | Wide horizontal, narrow vertical |
| Side-Firing 180° | Used for double-sided boxes |
| Prism Lens | Optimized for diffusion in textiles |
🧠 Tip: Use a diffuser fabric or acrylic to blend light and eliminate hotspots near the LED source.
📏 Spacing & Depth Guidelines
| Lightbox Depth | Recommended Type | Throw Distance (1 side) |
|---|---|---|
| 25–50mm | Narrow-beam modules | Up to 300mm |
| 50–80mm | Linear bars | 400–600mm |
| 80–150mm | High-power side bars | 700–1200mm |
🔁 Double-sided lightboxes often use back-to-back sidelight bars, mounted on a central spine or at opposing edges.
⚙️ Voltage & Power Planning
| Voltage | Application Size | Notes |
|---|---|---|
| 12V | Small signs | High current, short runs |
| 24V | Standard fabric boxes | Most common, better efficiency |
| 48V | Large systems | Long cables, less voltage drop |
Typical Power:
- Modules: 1.0–2.5W each
- Bars: 6W–18W per bar (depending on length)
🛠 Mounting Techniques
| Type | Mounting Method | Notes |
|---|---|---|
| Sidelight Bar | Screw or snap-in bracket | Use aluminum extrusion for heat |
| Module | 3M tape or screw | Aim lens across surface |
| Double-sided | Mount facing each side | Needs structural center support |
🧱 For fabric lightboxes, place modules/bars along the inside frame rails, and secure firmly to avoid sag or shift.
💧 IP Ratings
| IP Rating | Environment | Use Case |
|---|---|---|
| IP20 | Indoor, dry | Retail and textile frames |
| IP65 | Humid environments | Bathrooms, semi-covered areas |
| IP67 | Outdoor signage | Must be sealed + UV protected |
🎛 Control Options
- PWM Dimming — For brightness control
- 0–10V / DALI — For building-integrated systems
- DMX — For creative zones or animated textile signs
🧠 Sidelight vs Backlight — Quick Comparison
| Feature | Sidelight (Edge-Lit) | Backlight (Rear-Mounted) |
|---|---|---|
| Depth Needed | Low (25–80mm) | Medium to deep (60–150mm+) |
| Uniformity | Requires good diffuser | Easier to achieve with spacing |
| Install Speed | Faster for large boxes | More setup for modules |
| Parts Needed | Fewer, but precise aiming | More, but flexible layout |
🧰 Example: 1.2 × 2m Fabric Lightbox
- Frame Depth: 60mm
- Type: Single-sided textile
- Solution:
- 2 × 24V side bars (mounted on vertical sides)
- 12W per bar
- Total power: ~24W
- Driver: 36W 24V with PWM dimming
💡 Add a light-blocking rear panel or foil to reduce back spill and increase forward intensity.
📦 Key Takeaways
✅ Use edge-lit bars or narrow-beam modules for:
- Textile lightboxes (retail, museum, décor)
- Slim acrylic lightboxes
- Double-sided fabric signage
- Large format frames (when used in pairs)
⚠️ Avoid sidelight for:
- Ultra-deep boxes (use backlight instead)
- Unstructured fabric frames (bar sag can occur)
🛠 Still Need Help?
Send us your frame dimensions and lighting needs — we’ll help you plan the best sidelight or backlight layout.