Illumination types for illuminated signs: front-lit, halo & side-lit explained

Whether a sign looks refined by day, stays legible from 50 metres at night or quietly enhances a reception area depends above all on the type of illumination. With illuminated letters and illuminated signage, the key question is which side the light comes from: the front, the back, the sides or through a printed surface. Here you can find out how each variant is built, how it looks and which application it suits.

Front-lit: maximum legibility

With front-lit letters, the LEDs sit inside a closed letter body and the face is made of opal acrylic. The light shines evenly forwards while the side walls (returns) stay dark. This construction is the standard for façades because it has the greatest long-distance impact – the lettering stays clearly legible even from far away.

Front-lit letters come in a classic version with a trim cap, a rimless version for a pared-back look, or with a vacuum-formed, domed face for a sculpted effect. You can find an overview on the Front-lit letters page. Light boxes are essentially front-lit too: here a printed surface is lit across its whole area.

When front-lit is the right choice

• Façades facing streets, car parks and in shopping centres
• Coloured logos that should appear in their brand colour at night as well
• Long viewing distances

Back-lit (halo): indirect and elegant

With back-lit letters, the face is closed, usually in painted aluminium or stainless steel. The LEDs shine backwards onto the wall, creating a soft ring of light around every letter – known as halo lighting. The lettering itself appears as a silhouette against the light.

Halo letters look premium and do not dazzle. They are the preferred solution for reception areas, hotels, medical practices and law firms. They need a wall clearance of about 3–5 cm – which is why back-lit letters are always mounted on standoffs. The effect works best on light, smooth walls. Find out more on the Acrylic back-lit letters & halo logos page.

Front and back-lit: the best of both

A front and back-lit letter shines both forwards and backwards. The opal face ensures legibility, while the translucent back creates the halo. The result looks three-dimensional and especially striking – ideal for restaurants, bars, gyms and anyone who wants to stand out in the evening. Face and halo can even be made in different light colours. Details on the Front & back-lit letters page.

Side-lit: the glowing outline

With side-lit acrylic letters, the face is covered and the light escapes only at the edges. The lettering shows as a fine line of light, and by day the face displays your chosen colour or a metal finish. If the face is lit as well, the letter is called front and side-lit – the whole letter then looks like a body of light.

These variants are particularly suited to interiors, shop windows and sheltered outdoor areas. As no metal body is needed, smaller lettering is easy to produce too. See Channel letters and Acrylic & flat letters.

Double-sided: for projecting signs and light boxes

Double-sided signs have two illuminated faces and are mounted at right angles to the façade, so passers-by see your logo from both directions. Typical examples are illuminated projecting signs and double-sided light boxes in pedestrian zones.

LED neon: light as a line

With LED neon signs, it is not a surface that glows but a line. Flexible LED neon tubes are shaped and mounted on acrylic. This creates the classic neon look – more modern, more economical and more robust than glass neon. LED neon lights up instantly and evenly. A dimmer and remote control are included with every sign. With RGB versions, the whole sign changes colour together.

Non-illuminated: 3D and 2D

Not every sign has to light up. 3D letters in stainless steel or painted metal make their impact through depth and shadow, flat metal letters through precision and material. If needed, they can be lit with spotlights. Moss logos and fascia signs also work without their own illumination.

Illumination types compared

Don't forget the daytime look

A sign is seen in daylight most of the time, so it pays to think about how it looks when switched off. By day, front-lit letters show the colour of their acrylic face, halo letters their painted or metallic face, and side-lit letters their covered face colour. With a special day/night film, a face can look dark by day and glow white at night – popular for black logos. That is why the Sign type guide shows every version both switched on and switched off.

LED technology: economical and long-lasting

All our illuminated signs use LED technology. LEDs reach full brightness instantly, produce little heat and use only a fraction of the energy of classic fluorescent tubes or glass neon. Depending on the sign type, the power supply is concealed in the wall, in a mounting rail or behind the sign. With a timer or a dusk sensor, your illuminated signage can switch on and off automatically.

How to find the right illumination

1. Viewing distance

If your sign needs to be read from the street, a front-lit or combined version is usually the best choice. As a rule of thumb, allow about 10 cm of letter height per 10 m of distance. For reception walls, on the other hand, halo or side-lit letters are often enough.

2. Wall and surface

Halo effects need a light, ideally smooth wall. On dark facing brick or coarse render, a front-lit letter is often more effective.

3. Brand impact

If your logo should appear in its colours at night, front-lit is ideal. If you want elegance rather than signal effect, halo or stainless steel is the better fit.

4. Light colour

Warm white looks inviting and suits hospitality, hotels and wood. Cool white looks clear and modern. Coloured light adds accents – for example a white halo behind a coloured face.

Not sure? Send us your logo – in a free design preview we will show you how your sign looks with the right illumination. You can find an overview of all versions in the Sign type guide, and everything about fixing on the Mounting methods page.