To light a display cabinet you already own, run a diffused LED strip along the inside top front edge of each shelf, powered from a single low-voltage supply, with the wire routed down a rear corner. Front edge, not back. That one decision accounts for most of the difference between a cabinet that looks lit and one that looks like it has a light in it.
This is an installation guide for retrofitting a cabinet - an IKEA Detolf or Milsbo, a glass curio, a bookcase with doors. If you are choosing a light on specification rather than fitting one, start with the three numbers that matter instead.
Buy on three specs, then stop reading spec sheets
Before any of the installation detail, the strip itself has to be right, and cheap strip lighting is usually wrong on all three counts:
- 4000 K. Neutral white. Warm 2700-3000 K puts an amber cast over everything and turns white items cream; 6500 K looks like a retail fridge.
- 90+ CRI. Below about 80, reds go flat and metallic finishes stop reading as metallic. This is the spec most retrofits get wrong, and it is the reason a collection can look worse in its lit cabinet than it did in your hand.
- No UV. LEDs emit far less than daylight, but "far less" is not "none" on unbranded strip. UV is what yellows light plastics and fades printed inks over years.
Where to put the strip
Top front edge, facing back
The default, and correct for almost every cabinet. The strip sits behind the front rail where the viewer cannot see it, and throws light onto the front faces of what is on the shelf - the faces you actually look at.
Not the back wall
Back-mounted strip silhouettes everything. It looks dramatic in a photo of the cabinet and useless when you want to see an object.
Not a single strip at the very top
One strip in the cabinet roof lights the top shelf well and the bottom shelf barely, because light falls off with distance and each shelf shades the one below. Every shelf needs its own run.
Sides, only for deep cabinets
In a cabinet deeper than about 30 cm, adding short vertical runs at the front corners fills the shadows a top strip leaves. In a shallow cabinet they just create glare on the glass.
Diffusion is not optional
Bare LED strip produces a row of visible dots and hard-edged shadows. An aluminium channel with a frosted cover - sold for a few dollars per metre, cut to length with a hacksaw - turns it into a line of light and hides the strip completely. It also gives you something rigid to mount, which matters more than it sounds: adhesive-backed strip stuck straight to glass or melamine reliably peels within a year as the adhesive warms and cools.
Powering it without a visible mess
Most retrofits look untidy for one reason: each shelf gets its own plug-in adapter. Do it once, properly:
- One supply for the whole cabinet. Add up the strip wattage - typically a few watts per metre - and pick a 12 V or 24 V supply comfortably above the total.
- Wire the shelf runs in parallel back to that one supply, rather than chaining one shelf off the end of another. Chained runs get dimmer along the chain.
- Route down a rear corner. In a glass cabinet, the rear corner post is the only vertical line already there. Cable clips at 15-20 cm intervals, all on the same vertical line - a wire that follows an existing edge disappears; one that wanders across the back does not.
- Exit at the bottom rear and put the supply behind or under the cabinet.
- Add a switch or a sensor in line. Lighting a cabinet all day is wasted exposure on the contents; a motion sensor or a remote means the light is only on when someone is there. We compared the options in motion sensor vs switch vs always-on.
Glass-cabinet specifics
A glass cabinet is a harder lighting job than a solid-sided one, for two reasons.
Reflections. Every glass panel reflects the strip. If you can see the light source in the front glass from where you normally stand, move the strip further behind the front rail or add deeper diffusion - do not move the objects. Lighting a glass cabinet is mostly an exercise in hiding the source.
Nowhere to hide the wire. Solid cabinets let you drill through a shelf. In a glass cabinet the wire is visible from every angle, which is exactly why the single rear-corner route matters. Use a wire that matches the frame colour - black on a black frame is nearly invisible; white is not.
Worth saying plainly: cabinet glass gives you dust protection, not UV protection. It has the same transmission problem as window glass, so keep the cabinet out of direct sun regardless of what you fit inside it. That is covered in can you display diecast near a window.
Heat
LEDs run cool compared to what they replaced, but a sealed cabinet with several metres of strip and a driver inside still warms up, and the aluminium channel above is doing double duty as a heatsink. Keep the driver outside the cabinet. Soft vinyl, rubber tyres and adhesives are the materials that care about sustained warmth; metal and painted resin do not.
When retrofitting is the wrong answer
A retrofit lights a cabinet evenly. It does not make any single piece a hero - everything gets the same light, which is the nature of shelving. If the goal is for one piece to stand out, a separate lit enclosure does that and a strip never will. That is the trade we describe in the best display for a single model car, and it is the reason our own case is built as a one-object enclosure with the light already inside it rather than as a cabinet accessory. Specifications are on the specs page.
FAQ
Where should LED strip go in a display cabinet?
Along the inside top front edge of each shelf, facing back into the cabinet, hidden behind the front rail. Back-mounted strip silhouettes the contents, and a single strip at the top of the cabinet leaves the lower shelves dim.
Do I need a light on every shelf?
Yes, in any cabinet with more than two shelves. Light falls off with distance and each shelf shades the one below it, so one run at the top produces a bright top shelf and a dim bottom one.
Why does my cabinet lighting look cheap?
Usually two causes: bare strip with no diffuser, which gives visible dots and hard shadows, and low CRI, which flattens reds and kills metallic finishes. An aluminium channel with a frosted cover and a 90+ CRI strip fixes both.
How do I hide the wires in a glass cabinet?
Route everything down one rear corner post - the only vertical line already in the cabinet - with clips every 15-20 cm, and use wire that matches the frame colour. Exit at the bottom rear and keep the power supply outside the cabinet.
Will LED lighting damage my collection?
A UV-free LED at sensible brightness is the safest artificial light available. The real risks are ultraviolet and sustained heat, both far higher in direct daylight than in any indoor strip - so cabinet placement matters more than the strip you choose.