I’m backlighting a resin panel — how far back should the LED sheet go, and can I check it with a sample first?
I want to backlight my resin panel, but I don’t want to see individual dots through the front — so how far back should the sheet sit? There is no one distance for every resin panel. A gap that looks even behind one panel can show dots behind another, because type, thickness, colour, and particles change how light spreads. Start from the stone bands, then test behind the actual panel you will install.
Why my panel won’t behave like stone
Type changes how light spreads, thickness changes how much reaches the front, and colour shifts it again: pale resin glows easily, deep colour swallows light and leaves the face uneven. Flakes, veins, and chips block light in one spot and pass it in another, so one panel differs area to area, and batch and pigment load can differ between panels.
What distance do I start from?
For stone, high-density sheets start at 30–50mm and standard-density sheets sit around 50mm, with the final result always depending on a sample test with the real stone. For resin, use that stone distance guidance as a starting range to test, not a finished answer. Closer is brighter but risks dots; farther is softer, but dimmer and needs a deeper cavity. Keep the sheet flat and the gap true — a sag or tilt toward the panel reads as a hotspot in that corner. Leave 2mm at the 1.6mm-thick glowing area, and 6mm where the 5.6mm connector sits, so it does not push the sheet out of plane.
How do I test it behind my actual panel?
Test behind the real panel, not a swatch or an offcut from another batch. If panels will join into one lit area, test across a joint, with joined flexible PCB LED light sheets, not a single sheet alone. At each distance, look for:
- Dots or a grid, especially close up and straight on.
- Bright patches or streaks, often near the centre or a join.
- Dark or dull areas where resin is densest or most filled.
- Colour shift, where one area looks warmer, cooler, or more saturated.
Check the densest, darkest, and most coloured areas on purpose — testing only the palest part hides the failure you will see after installation. Check from angles too: a face clean head-on can show dots at an angle. Judge it in the room’s real lighting, not only a dark workshop, and at the dimmed level you actually plan to use, since unevenness can appear when brightness drops. Note gap, angle, and room light at each step.
Do I need a diffuser?
A diffuser between sheet and panel spreads light and can soften dots, so it can rescue a gap that is slightly too tight. It will not fix uneven blocking, and it takes brightness away, so a heavy diffuser plus a deep gap can end up too dim. Test with the diffuser you plan to install, in the same position, and re-check the gap if you change it. Settle white and wiring first — the wrong white can mislead a distance test. BG-0318 RGBCCT: 490×245mm, 24V, 50W, 640 LEDs, 2700K and 6000K whites, 6 cores (V+/R/G/B/warm/cool). BG-0313 RGBW: 45W, 512 LEDs, white only 3000K or 6000K, 5 cores.
What should I send?
Send the panel details, not just a description of it:
- Resin type, supplier, colour, and photos of the front and back of the actual panel.
- Thickness, size, and whether thickness or density varies across the piece.
- Cavity depth you can build, including diffuser and fixings inside it.
- Room lighting and the brightness level you plan to run.
- Distances tried, and where dots, bright patches, or dark areas appeared.
If batch, cavity, or diffuser is undecided, say so and confirm before ordering.
FAQ
Can I just use the stone distance for resin?
Use it to start a test, not as the finished answer. Resin type, thickness, colour, and particles change how light spreads, so confirm the gap behind your actual panel.
Why does one panel look different in different areas?
Dense, dark, or filled areas scatter light differently from pale, clear areas, so one part can glow evenly while another shows dots at the same gap.
Should I test in the dark or in normal room light?
Both, but judge it in the room’s real light. Dark-room testing shows dots; room light shows whether the glow still reads under daylight and overhead lights.
Get the gap right before you commit
Start from the stone bands, test your actual panel in its real lighting, and settle diffuser and gap together. Then request a quote or a sample with the panel details and test notes above, so the answer is based on your panel, not a generic figure.